Sex related differences in short and long-term prognosis after acute myocardial infarction: 10 year follow up of 3073 patients in database of first Danish Verapamil Infarction Trial.

OBJECTIVE--To re-examine the prevailing hypothesis that women fare worse than men after acute myocardial infarction. DESIGN--10 year follow up of all patients with confirmed acute myocardial infarction registered in the database of the Danish verapamil infarction trial in 1979-81. SETTING--16 coronary care units, covering a fifth of the total Danish population. PATIENTS--3073 consecutive patients with acute myocardial infarction, 738 (24%) women and 2335 (76%) men. MAIN OUTCOME MEASURES--Early mortality (before day 15). For patients alive on day 15: mortality, cause of death, admission with recurrent infarction, and mortality after reinfarction. RESULTS--Early mortality increased significantly with age (P < 0.0001) but was not significantly related to sex, with a 15 day mortality of 17% in women and 16% in men. Adjustment for age and sex simultaneously revealed a significant interaction (P = 0.02) between these variables, with a greater increase with age in early mortality for men than for women (early mortality was equal for the two sexes at age 64 years). Ten year mortality in patients alive on day 15 was 58.8%. The overall age adjusted hazard ratio (95% confidence interval) for women versus men was 0.90 (0.80 to 1.01); 0.90 (0.78 to 1.04) for 10 year reinfarction (48.8%); and 0.98 (0.82 to 1.16) for 10 year mortality after reinfarction (82.3%). No difference in cause of death was found between the sexes. With a follow up of up to 10 years for patients alive on day 15 mortality, rate of reinfarction, and mortality after reinfarction increased with increasing age (P < 0.0001). CONCLUSION--Sex by itself is not a risk factor after acute myocardial infarction.     

A new technique of coronary artery ligation: Experimental myocardial infarction in rats in vivo with reduced mortality

In vivo models of myocardial infarction following coronary artery ligation in the rat still suffer from high early mortality and a low rate of success of myocardial infarction. This study investigated the possibility of reducing early mortality and increasing the rate of myocardial infarction by modifications of surgical techniques. Eighteen rats were divided into two groups: normal control (3 rats) and ligation (15 rats). The major modifications of surgical techniques used in this study include: (1) no exteriorization of the heart, (2) ligation of the origins of the branches rather than the main trunk of the left coronary artery, (3) removal of air from the chest after closure, (4) supplying oxygen immediately after extubation. Following surgery, the rats recovered uneventfully and 11 rats were alive after 16 weeks. One rat, with a large myocardial infarction, died 2 h after surgery. Early mortality (during surgery and 1 week after surgery) was 6.7% with a success rate of myocardial infarction of 85%. The left ventricle in the ligation group showed significant dilation relative to normal and shamoperated control hearts (317% of control hearts, p < 0.001). However, myocardial mass did not increase. The average infarct size was 33%. These results demonstrate that a reduction in early mortality and an increased success rate of myocardial infarction can be achieved by modifications of surgical techniques.     

MYOCARDIAL INFARCTION FOLLOWING CAROTID ENDARTERECTOMY

Myocardial infarction has been the major cause of mortality following operation for cerebrovascular insufficiency. In our institution, a clinical diagnosis of coronary artery disease was made in 37 of 125 (29.6%) consecutive male patients having carotid endarterectomy. Six of these 37 patients developed postoperative myocardial infarction. In contrast, none of the 88 patients without coronary artery disease developed myocardial infarction. A more recently treated group of 20 patients who had undergone carotid artery surgery and had previously undergone coronary artery bypass for angina did not develop postoperative myocardial infarction. These data suggest that in patients with both coronary artery and carotid artery disease, prior or concomitant coronary artery bypass should be considered. Myocardial infarction has been the leading cause of early and late death following operation for cerebrovascular insufficiency.(1) DeBakey(2) found operative mortality in patients having surgery for cerebrovascular insufficiency directly related to the incidence of coronary artery disease. An increased operative mortality due to reinfarction has been found in patients recovering from recent myocardial infarction.(3) Cooley(4) found that in patients having aortocoronary bypass there was no increased operative mortality 30 days after myocardial infarction and this may apply to patients having carotid endarterectomy. Subendocardial postoperative infarction associated with minor T wave changes and slight enzyme elevation had a better prognosis than did transmural infarction causing significant Q waves, sequential ST and T wave changes and marked enzyme elevations.(5) The purpose of this study was to document our experience with myocardial infarction in patients undergoing carotid artery operation for clinical coronary artery disease. Consideration of the role of saphenous vein bypass in those patients with coronary artery disease was the background for this review even though the evidence that myocardial infarction can be prevented with saphenous vein bypass operation is only preliminary at the present time.(6)     

Mortality rate in subsequent years following myocardial infarction]

Eight hundred out of 997 patients with myocardial infarction hospitalized at cardiological ward in Kielce in 1977-1985 survived. Seven hundred seventy one patients were followed up for 2-10 years. Basing on the obtained results, tables of the mortality rates and probability of survival depending on sex, age, and classification into appropriate prognosis group have been prepared. The highest mortality rate (9.6%) was seen in the first year following myocardial infarction. Mean annual mortality rate in this group was 6% during 10 years of the follow up. Mortality rate in women with myocardial infarction was significantly lower than in men during 10 years of the follow up.     

Shock Following Myocardial Infarction: A Clinical Survey of 140 Cases

All admissions for acute myocardial infarction to a metropolitan general hospital over a 10-year period have been reviewed. One hundred and forty patients developed complications meeting the criteria for cardiogenic shock. The mortality rate in this group of patients was 83%. The mortality rate in 95 patients who received treatment with intravenous noradrenaline was no different from that in 45 patients who did not receive this type of therapy (p = >0.8). Patients dying from cardiogenic shock were younger than those dying of other complications. Autopsy study of this group of shocked patients revealed a significantly lower incidence of previous healed myocardial infarction (p = <0.01).A decline in the annual incidence of cardiogenic shock was noted over the decade surveyed. It is suggested that this may be due to the earlier and more frequent use of intravenous noradrenaline. Despite the reduction in the incidence of shock, the annual mortality rate from myocardial infarction has remained unaltered.     

Specific and gender differences between hospitalized and out of hospital mortality due to myocardial infarction

In this paper, the authors evaluate gender related differences of myocardial infarction mortality before and after hospital admittance. Myocardial infarction mortality in the Clinical Hospital Split in the seven years period between 2000 and 2006, have been analyzed together with out of hospital sudden death patients with acute myocardial infarction established during autopsy. During the seven year period between 2000 and 2006, 3434 patients were treated for myocardial infarction in the Split Clinical Hospital, 2336 (68%) males and 1098 (32%) females with a 12% total mortality (427 patients). The annual number of hospitalized persons has been increasing during that period (474 in yr. 2000 us. 547 in yr. 2006), while mortality decreased from 15% in 2000 to 9.6% in 2006. Female patients had significantly higher hospital mortality than male patients, (228 or 21% vs. 202 or 9%, p<0.05). Women also had significantly higher total AMI mortality (23.7% vs. 15,7%, p <0.05). Anterior myocardial infarction with ST elevation in precordial leads had significantly higher mortality (19%) compared to patients with lateral (11%), inferior (10%) myocardial infarction with ST elevation and also NSTEMI (4%) mortality p<0.05. Female patients more frequently die in hospital, 84% (230) than out of hospital 16% (43). From the total number of AMI deaths (388) in male patients, 56% (217) were in hospital and 44% (171) out of hospital (p<0.001). Men had significantly higher prehospital mortality rate than women (81% vs. 19%, p<0.05). Men also more frequently died from ventricular fibrillation (22% vs. 10%, p<0.05), while women died more frequently of heart failure, cardiogenic shock, and myocardial rupture (33% vs. 15% p<0.05). Regarding the total number of deaths from myocardial infarction men had significantly higher prehospital mortality compared to women (178 or 7.3% vs. 43 or 3.7%, p<0.05). Anterior myocardial infarction had a significantly higher rate in patients dying pre-hospital (58%), in contrast to inferior (36%) and lateral myocardial infarction with ST elevation (6%) p<0.05. We have concluded that male patients die more frequently within the first few hours of AMI mostly due to malignant arrhythmias, while female patients died in sub acute stage due to heart failure while being hospitalized. Nevertheless total mortality of AMI remains significantly higher in women.     

Results of Early Mobilization and Discharge after Myocardial Infarction

A total of 342 patients with acute myocardial infarction who were admitted to a coronary care unit are reviewed to assess the results of early mobilization and discharge. The mean duration of admission was 8·4 days and 89% of the survivors were discharged from hospital by the tenth day. The inpatient mortality was 15·5%. An additional 6·7% died during the six weeks'' follow-up period, giving a total mortality of 22·2%. Altogether, 7·6% of patients were readmitted. Venous thromboembolic phenomena occurred in 3·5% during the inpatient period. Of patients who were eligible 62% were back at work five months after their myocardial infarction. We think the results justify a short hospital admission period for acute myocardial infarction.     

Ischaemic Heart Disease: A Secondary Prevention Trial Using Clofibrate

A trial is reported of the effects of giving clofibrate to prevent progression of pre-existing ischaemic heart disease. There were two groups randomly distributed between clofibrate (350 patients) and placebo (367 patients) regimens. The trial lasted about six years and was conducted in 19 hospitals in Scotland. The criteria of acceptance into the trial were precise and were monitored by one observer. The standards of diagnosis of events were defined and all protocols and electrocardiograms were read blind by one observer.Three categories of patients were admissible to the trial: (1) patients with one myocardial infarction (W.H.O. E.C.G. criteria) between 8 and 16 weeks before the start of the trial; (2) patients with angina of a duration of 3 to 24 months, provided their E.C.G. showed signs of myocardial ischaemia at rest or after exercise; and (3) patients with one recent myocardial infarction and pre-existing angina as defined above.There were fewer deaths in patients with angina (categories 2 and 3 above) treated with clofibrate than in those on placebo. The mortality in the former group was reduced by 62%, and this is a statistically significant difference. Clofibrate did not have any statistically significant effect in reducing the rate of non-fatal infarction in patients with angina or in those with myocardial infarction and pre-existing angina, though a beneficial trend was evident when both subgroups were combined (a 44% reduction compared with the placebo group). There was a significant reduction in all events (fatal and non-fatal) in patients with angina (“all anginas”) in the clofibrate-treated group; the rate was reduced by 53%.Clofibrate did not alter the overall mortality or morbidity rates in patients admitted to the trial with recent myocardial infarction without preceding angina of more than three months'' duration. In one subgroup there was a statistically significant adverse effect in the clofibrate-treated group. The lack of any overall effect in patients with myocardial infarction might be related to the unexpectedly low mortality rate (2·97%) in the placebo group; it is usually in the region of 4-9% per annum after first myocardial infarction.In patients categorized as “all anginas” there was significant reduction in events whether the initial serum cholesterol level was high (greater than 260 mg/100 ml) or normal. Clofibrate seemed to have a small but not significant beneficial effect in patients with myocardial infarction with initially high serum cholesterol levels, but was of no value in those with initially normal serum cholesterol levels. There was no significant relationship between the response or lack of response of serum cholesterol to clofibrate and the incidence of events either in patients with angina or in those with infarction.The main conclusion of this trial is that clofibrate had a beneficial effect in reducing mortality and, to a lesser extent, morbidity in patients who presented with angina (“all anginas”). This effect was independent of initial serum cholesterol levels or the extent to which serum cholesterol was lowered. The drug had no significant overall effect on prognosis in patients with myocardial infarction alone.     

Inpatient deaths from acute myocardial infarction, 1982-92: analysis of data in the Nottingham heart attack register.

OBJECTIVE: To assess longitudinal trends in admissions, management, and inpatient mortality from acute myocardial infarction over 10 years. DESIGN: Retrospective analysis based on the Nottingham heart attack register. SETTING: Two district general hospitals serving a defined urban and rural population. SUBJECTS: All patients admitted with a confirmed acute myocardial infarction during 1982-4 and 1989-92 (excluding 1991, when data were not collected). MAIN OUTCOME MEASURES: Numbers of patients, background characteristics, time from onset of symptoms to admission, ward of admission, treatment, and inpatient mortality. RESULTS: Admissions with acute myocardial infarction increased from 719 cases in 1982 to 960 in 1992. The mean age increased from 62.1 years to 66.6 years (P < 0.001), the duration of stay fell from 8.7 days to 7.2 days (P < 0.001), and the proportion of patients aged 75 years and over admitted to a coronary care unit increased significantly from 29.1% to 61.2%. A higher proportion of patients were admitted to hospital within 6 hours of onset of their symptoms in 1989-92 than in 1982-4, but 15% were still admitted after the time window for thrombolysis. Use of beta blockers increased threefold between 1982 and 1992, aspirin was used in over 70% of patients after 1989, and thrombolytic use increased 1.3-fold between 1989 and 1992. Age and sex adjusted odds ratios for inpatient mortality remained unchanged over the study period. CONCLUSIONS: Despite an increasing uptake of the "proved" treatments, inpatient mortality from myocardial infarction did not change between 1982 and 1992.     

Evolution précoce et tardive après pontage aortocoronarien: expérience de 500 cas.

Between 1971 and 1976, 500 patients underwent aortocoronary bypass surgery. There were 15 operative deaths (3%) and the total frequency of perioperative infarction was 7%. The operative mortality was 7.4% in unstable angina, as compared with 1.1% in stable angina (P less than 0.01). The proportion of grafts patent at 2 weeks was 92% and at 18 months 87.6%. Postoperative follow-up was complete for 99% of the patients. There were 15 late deaths (3%) and the rates of survival at 2 and 4 years were 94.4% and 92.1% respectively. The actuarial curve of survival after surgery was not significantly different from that of the general population. After a mean follow-up of 27 months 73% of the patients were completely free of angina and 19% were markedly improved. The rate of recurrence of angina averaged 10% per year and the annual infarction rate was 0.7%. Fourteen patients (3%) underwent reoperation during the follow-up period. Thus, coronary revascularization surgery offers effective and sustained relief of incapacitating angina and might also improve survival if the operative mortality is low.     

Isolated Aortocoronary Bypass Operations in Patients Over 70 Years of Age: A Comparison With Results in Patients 50 to 59 Years Old

The early and late morbidity, mortality and beneficial effects of isolated aortocoronary bypass operations in a group of 35 patients 70 years old or older were compared with those factors in patients 50 to 59 years old. The patients in both groups were matched according to the year in which the operation was done and the number of vessels bypassed. Left ventricular function, estimated by the angiographically calculated ejection fraction, was not statistically different in the two groups. Cardiac index, while adequate in both groups, was significantly lower in the older age group. Comparisons were made of “early” events, such as perioperative myocardial infarction, perioperative death and length of post-operative hospital stay; and of “late” events, including myocardial infarction, angina pectoris, congestive heart failure and death, which occurred after patients were discharged from the hospital. The mean length of follow-up of patients was similar in both groups.In comparing early events in the two groups, there was no statistically significant difference in the incidence of perioperative myocardial infarction, perioperative mortality or mean length of postoperative hospital stays. With regard to late events, there was no statistically significant difference in the incidences of myocardial infarction, angina pectoris or mortality.     

Risks and benefits of aortocoronary bypass surgery in patients aged 65 years or more.

Between January 1970 and July 1978, 85 patients aged 65 years or more underwent aortocoronary bypass surgery at the Montreal Heart Institute. The mortality during the operation and the first 29 days thereafter was 12% overall, but was only 5% when the myocardium was protected by the use of cold cardioplegic solutions. Of the 75 patients who survived this period 7 (9%) had a perioperative transmural myocardial infarction. Nonfatal noncardiac complications were more common in these patients than in younger patients, but did not lead to permanent deficits. Three patients died after discharge from hospital, two of cardiac causes. Only one patient had a nonfatal myocardial infarction after discharge. The actuarial 5-year survival rate for all the patients was 80%. After a mean follow-up period of 30 months the condition of 94% of the patients was improved by at least one class of the New York Heart Association functional classification, and 68% were asymptomatic. It is concluded that aortocoronary bypass surgery can be performed in selected older patients with a relatively low in-hospital mortality and morbidity. Symptomatic improvement occurs in almost all such patients. Cardiac catheterization and aortocoronary bypass surgery should therefore be performed in selected older patients with severe angina that is refractory to optimum medical therapy.     

Association of Left Ventricular Mass with All-Cause Mortality,Myocardial Infarction and Stroke

Background

Our aim was to assess the association of left ventricular mass with mortality and nonfatal cardiovascular events.

Methodology/Principal Findings

Left ventricular mass was measured by echocardiography in 40138 adult patients (mean age 61.1±16.4 years, 52.5% male). The primary endpoint was all-cause mortality. Secondary endpoints included nonfatal myocardial infarction and nonfatal stroke. During a mean follow-up period of 5.6±3.9 years, 9181 patients died, 901 patients had a nonfatal myocardial infarction, and 2139 patients had a nonfatal stroke. Cumulative 10-year mortality was 26.8%, 31.9%, 37.4% and 46.4% in patients with normal, mildly, moderately and severely increased left ventricular mass, respectively (p<0.001). Ten-year rates of nonfatal myocardial infarction and stroke ranged from 3.2% and 6.7% in patients with normal left ventricular mass to 5.3% and 12.7% in those with severe increase in left ventricular mass, respectively. After multivariate adjustment, left ventricular mass remained an independent predictor of all-cause mortality (hazard ratio [HR] per 100 g increase 1.21, 95% confidence interval [CI] 1.14–1–27, p<0.001 in women, and HR 1.09, 95% CI 1.04–1–13, p<0.001 in men), myocardial infarction (HR 1.60, 95% CI 1.31–1.94, p<0.001 in women and HR 1.15, 95% CI 1.02–1.29, p = 0.019 in men) and stroke (HR 1.26, 95% CI 1.13–1.40, p<0.001 in women and HR 1.19, 95% CI 1.09–1.30, p<0.001 in men).

Conclusions/Significance

Left ventricular mass has a graded and independent association with all-cause mortality, myocardial infarction and stroke.     

Intra-aortic balloon counterpulsation in acute myocardial infarction: old and emerging indications

Background

Recent evidence questions the role of intra-aortic balloon counterpulsation (IABP) in the treatment of acute myocardial infarction (AMI) complicated by cardiogenic shock (CS). An area of increasing interest is the use of IABP for persistent ischaemia (PI). We analysed the use of IABP in patients with AMI complicated by CS or PI.

Methods

From 2008 to 2010, a total of 4076 patients were admitted to our hospital for primary percutaneous coronary intervention (PCI) for AMI. Out of those, 239 patients received an IABP either because of CS or because of PI. Characteristics and outcome of those patients are investigated.

Results

The mean age of the study population was 64 ± 11 years; 75 % were male patients. Of the patients, 63 % had CS and 37 % had PI. Patients with CS had a 30-day mortality rate of 36 %; 1-year mortality was 41 %. Patients with PI had a 30-day mortality rate of 7 %; 1-year mortality was 11 %.

Conclusions

Mortality in patients admitted for primary PCI because of AMI complicated by CS is high despite IABP use. Outcome in patients treated with IABP for PI is favourable and mandates further prospective studies.     

Trial of early nifedipine in acute myocardial infarction: the Trent study.

Over 30 months 9292 consecutive patients admitted to nine coronary care units with suspected myocardial infarction were considered for admission to a randomised double blind study comparing the effect on mortality of nifedipine 10 mg four times a day with that of placebo. Among the 4801 patients excluded from the study the overall one month fatality rate was 18.2% and the one month fatality rate in those with definite myocardial infarction 26.8%. A total of 4491 patients fulfilled the entry criteria and were randomly allocated to nifedipine or placebo immediately after assessment in the coronary care unit. Roughly 64% of patients in both treatment groups sustained an acute myocardial infarction. The overall one month fatality rates were 6.3% in the placebo treated group and 6.7% in the nifedipine treated group. Most of the deaths occurred in patients with an in hospital diagnosis of myocardial infarction, and their one month fatality rates were 9.3% for the placebo group and 10.2% for the nifedipine group. These differences were not statistically significant. Subgroup analysis also did not suggest any particular group of patients with suspected acute myocardial infarction who might benefit from early nifedipine treatment in the dose studied.     

Baroreflex sensitivity determined by spectral method and heart rate variability, and two-years mortality in patients after myocardial infarction

Sympathetic overactivity and low parasympathetic activity is an autonomic dysfunction (AD) which enhances cardiac mortality. In the present study, the impact of AD on the mortality in patients after myocardial infarction was evaluated. We examined 162 patients 7-21 days after myocardial infarction, 20 patients of whom died in the course of two years. Baroreflex sensitivity (BRS) was estimated by spectral analysis of spontaneous fluctuations of systolic blood pressure and cardiac intervals (Finapres, 5 min recording, controlled breathing 20/min). The heart rate variability was determined as SDNN index (mean of standard deviations of RR intervals for all 5-min segments of 24-hour ECG recordings). BRS < 3 ms/mm Hg and/or SDNN index < 30 ms were taken as markers of AD. The risk stratification was performed according to the number of the following standard risk factors of increased risk of cardiac mortality (SRF): ejection fraction < 40%, positive late potentials and the presence of ventricular extrasystoles > 10/h. No difference in mortality between patients with AD (4%) and without AD (4.5%) was found in 92 patients without SRF, the mortality in 6 patients with three SRF was 66.6%. Five of these patients had AD. Out of 64 patients with one or two SRF, 32 had AD. The mortality of patients without AD was 6.25% and 31.2% of those with AD (p<0.025). It is concluded that AD enhanced two-years mortality five fold in our patients with moderate risks.     

Noncompliance in an exercise rehabilitation program for men who have suffered a myocardial infarction

A group of 163 men in the Hamilton, Ont. region who had suffered a myocardial infarction were enrolled in a rehabilitation program of physical activity. These men constituted one cohort of a multicentre collaborative study designed to determine the effects of regular exercise of differing intensity on morbidity and mortality over a 4-year period.The noncompliance rate was 43% for the men who could have participated for 1 year, 46% of whom were classified as noncompliers within 1 month of entry into the program. There was no difference in overall compliance between the men exercising at high intensity and those exercising at low intensity; lack of motivation or interest was the most common reason for their leaving the program. Those leaving the program early tended to have a type A behaviour pattern (they were aggressive, ambitious and competitive, with a chronic sense of time urgency), were inactive during their leisure time, had had at least two previous infarctions and smoked. These characteristics suggest that the men leaving the program early may have been those at greatest risk for a further myocardial infarction.     

Venous Graft Surgery in Treatment of Coronary Heart Disease

Sixty-seven patients have had aortocoronary venous graft bypass surgery by one surgeon for the relief of symptoms of severe coronary heart disease, including eight emergency operations. The overall operative, hospital, and late mortality was low in patients with favourable myocardial function and no previous myocardial infarction. There was a 7% mortality in patients with a normal preoperative chest radiogram, 8% mortality when the left ventricular end-diastolic pressure was normal preoperatively, and a 5% mortality in patients who had normal left ventricular angiograms. The overall mortality in all elective operations for cardiac pain resistant to medical treatment was 15·8%. 89% of survivors improved; 67% are pain-free. Exercise tolerance in survivors is increased by 135%, atrial pacing results are improved by 10%. Left ventricular end-diastolic pressure is unchanged. Left ventricular function on angiography is improved. The improvement in left ventricular function assessed objectively correlates positively with vein-graft patency, as does freedom from angina pectoris.     

Comparison of case fatality in south Asian and white patients after acute myocardial infarction: observational study.

OBJECTIVE--To compare mortality in south Asian (Indian, Pakistani, and Bangladeshi) and white patients in the six months after hospital admission for acute myocardial infarction. DESIGN--Observational study. SETTING--District general hospital in east London. PATIENTS--149 south Asian and 313 white patients aged < 65 years admitted to the coronary care unit with acute myocardial infarction from 1 December 1988 to 31 December 1992. MAIN OUTCOME MEASURE--All cause mortality in the first six months after myocardial infarction. RESULTS--The admission rate in the south Asians was estimated to be 2.04 times that in the white patients. Most aspects of treatment were similar in the two groups, except that a higher proportion of the south Asians received thrombolytic drugs (81.2% v 73.8%). After adjustment for age, sex, previous myocardial infarction, and treatment with thrombolysis or aspirin, or both, the south Asians had a poorer survival over the six months from myocardial infarction (hazard ratio 2.02 (95% confidence interval 1.14 to 3.56), P = 0.018), but a substantially higher proportion were diabetic (38% v 11%, P < 0.001), and additional adjustment for diabetes removed much of their excess risk (adjusted hazard ratio 1.26 (0.68 to 2.33), P = 0.47). CONCLUSION--South Asian patients had a higher risk of admission with myocardial infarction and a higher risk of death over the ensuing six months than the white patients. The higher case fatality among the south Asians, largely attributable to diabetes, may contribute to the increased risk of death from coronary heart disease in south Asians living in Britain.     

Myocardial Salvage is Reduced in Primary PCI-Treated STEMI Patients with Microvascular Obstruction,Demonstrated by Early and Late CMR

Objectives

This study evaluates the association between microvascular obstruction and myocardial salvage, determined by cardiac magnetic resonance performed both in the acute stage of myocardial infarction and after 4 months.

Methods

In patients with acute ST-elevation myocardial infarction treated by primary percutaneous coronary intervention, myocardial salvage, infarct size, left ventricular volumes, and ejection fraction were assessed by early (1–4 days) and follow-up (4 months) cardiac magnetic resonance. These variables were related to the presence or absence of microvascular obstruction at early investigation. Myocardial salvage was determined by: (1) myocardium at risk and infarct size measured in the acute stage and (2) myocardium at risk, measured acutely, and infarct size measured after 4 months. Multivariate analyses were performed, adjusting for clinical confounders at baseline.

Results

Microvascular obstruction was present in 49 of 94 included patients, (52%). Myocardial salvage was significantly reduced in patients with microvascular obstruction, compared to those without: 23% vs. 38%, measured acutely, and 39.8% vs. 65.4%, after 4 months (p<0.001). The presence of microvascular obstruction was significantly and independently associated with large infarct size, lower left ventricular ejection fraction, and larger left ventricular end-systolic volume.

Conclusion

The presence of microvascular obstruction demonstrated by cardiac magnetic resonance early after infarction was associated with impaired myocardial salvage. This association was more marked when based on measurement of infarct size after 4 months compared to assessment in the acute stage.