Infarct-related chronic total coronary occlusion and the risk of ventricular tachyarrhythmic events in out-of-hospital cardiac arrest survivors

IntroductionChronic total coronary occlusion (CTO) has been identified as a risk factor for ventricular arrhythmias, especially a CTO in an infarct-related artery (IRA). This study aimed to evaluate the effect of an IRA-CTO on the occurrence of ventricular tachyarrhythmic events (VTEs) in out-of-hospital cardiac arrest survivors without ST-segment elevation.MethodsWe conducted a post hoc analysis of the COACT trial, a multicentre randomised controlled trial. Patients were included when they survived index hospitalisation after cardiac arrest and demonstrated coronary artery disease on coronary angiography. The primary endpoint was the occurrence of a VTE, defined as appropriate implantable cardioverter-defibrillator (ICD) therapy, sustained ventricular tachyarrhythmia or sudden cardiac death.ResultsA total of 163 patients from ten centres were included. Unrevascularised IRA-CTO in a main vessel was present in 43 patients (26%). Overall, 61% of the study population received an ICD for secondary prevention. During a follow-up of 1 year, 12 patients (7.4%) experienced at least one VTE. The cumulative incidence rate of VTEs was higher in patients with an IRA-CTO compared to patients without an IRA-CTO (17.4% vs 5.6%, log-rank p = 0.03). However, multivariable analysis only identified left ventricular ejection fraction < 35% as an independent factor associated with VTEs (adjusted hazard ratio 8.7, 95% confidence interval 2.2–35.4). A subanalysis focusing on CTO, with or without an infarct in the CTO territory, did not change the results.ConclusionIn out-of-hospital cardiac arrest survivors with coronary artery disease without ST-segment elevation, an IRA-CTO was not an independent factor associated with VTEs in the 1st year after the index event.Supplementary InformationThe online version of this article (10.1007/s12471-021-01578-3) contains supplementary material, which is available to authorized users.     

Association of cytokines with endothelium dependent flow mediated vasodilation (FMD) of systemic arteries in patients with non-ischemic cardiomyopathy

Background

Takotsubo cardiomyopathy is an acute cardiac syndrome characterized by transient LV regional wall motion abnormalities (with peculiar apical ballooning appearance), chest pain or dyspnea, ST-segment elevation and minor elevations of cardiac enzyme levels

Case presentation

A 68-year-old woman was admitted to the Emergency Department because of sudden onset chest pain occurred while transferring her daughter, who had earlier suffered a major seizure, to the hospital. The EKG showed sinus tachycardia with ST-segment elevation in leads V2–V3 and ST-segment depression in leads V5–V6, she was, thus, referred for emergency coronary angiography. A pre-procedural transthoracic echocardiogram revealed regional systolic dysfunction of the LV walls with hypokinesis of the mid-apical segments and hyperkinesis of the basal segments. Coronary angiography showed patent epicardial coronary arteries; LV angiography demonstrated the characteristic morphology of apical ballooning with hyperkinesis of the basal segments and hypokinesis of the mid-apical segments. The post-procedural course was uneventful; on day 5 after admission the echocardiogram revealed full recovery of apical and mid-ventricular regional wall-motion abnormalities.

Conclusion

Takotsubo cardiomyopathy is a relatively rare, unique entity that has only recently been widely appreciated. Acute stress has been indicated as a common trigger for the transient LV apical ballooning syndrome, especially in postmenopausal women. The present report is a typical example of stress-induced takotsubo cardiomyopathy in a Caucasian Italian postmenopausal woman.     

Release patterns of copeptin and troponin in Tako-Tsubo cardiomyopathy

Copeptin, in addition to troponin, has recently been suggested for non-invasive differentiation between Tako-Tsubo cardiomyopathy (TTC) and acute myocardial infarction (AMI). In order to test this hypothesis, we investigated release patterns of pituitary copeptin and cardiac troponin in 49 patients with TTC and 49 age-, gender-, and ECG-matched control patients with AMI. Elevated copeptin levels (i.e. >12 pmol/l) at cardiac catheterization were found in 23/49 (47%) TTC patients and 25/49 (51%) AMI patients. Of these, median copeptin levels were almost identical in both cohorts (34.1 vs. 35.4 pmol/l). Subgroup analysis according to ECG changes revealed that AMI patients with ST-segment elevation had 3.6-fold higher copeptin levels than AMI patients without ST-segment elevation (p<0.05). Furthermore, in patients with TTC and atypical (midventricular) ballooning on left ventricular angiography, copeptin levels were 5.7-fold higher than in TTC patients with a typical (apical) type of ballooning (p<0.01). Elevated troponin T levels (i.e. >0.01 μg/l) at catheterization were detectable in 47/49 (96%) TTC patients and 45/49 (92%) AMI patients; however, peak levels did not differ significantly between both cohorts (median 0.35 vs. 0.27 μg/l). Subgroup analysis according to ECG changes revealed 2-fold higher peak troponin T levels in TTC patients presenting with ST-segment elevation than non-ST-segment elevation (p<0.05). In conclusion, copeptin does not seem to significantly increase non-invasive differentiation between TTC and AMI. At present, coronary angiography, specifically in patients with ST-segment elevation at presentation remains absolutely mandatory.     

STEMI or non-STEMI: that is the question

Acute coronary syndromes are usually classified on the basis of the presence or absence of ST elevation on the ECG: ST-elevation myocardial infarction or non-ST-elevation myocardial infarction (NSTEMI)patients with acute myocardial infarction (AMI) need immediate therapy, without unnecessary delay and primary percutaneous coronary intervention (PPCI) should preferably be performed within 90 min after first medical contact. However, in AMI patients without ST-segment elevation (pre) hospital triage for immediate transfer to the catheterisation laboratory may be difficult. Moreover, initial diagnosis and risk stratification take place at busy emergency departments and chest pain units with additional risk of ‘PPCI delay’. Optimal timing of angiography and revascularisation remains a challenge. We describe a patient with NSTEMI who was scheduled for early coronary angiography within 24 h but retrospectively should have been sent to the cath lab immediately because he had a significant amount of myocardium at risk, undetected by non-invasive parameters.     

High survival rate of 43% in out-of-hospital cardiac arrest patients in an optimised chain of survival

Aims

Survival to hospital discharge after out-of-hospital cardiac arrest (OHCA) varies widely. This study describes short-term survival after OHCA in a region with an extensive care path and a follow-up of 1 year.

Methods

Consecutive patients ≥16 years admitted to the emergency department between April 2011 and December 2012 were included. In July 2014 a follow-up took place. Socio-demographic data, characteristics of the OHCA and interventions were described and associations with survival were determined.

Results

Two hundred forty-two patients were included (73 % male, median age 65 years). In 76 % the cardiac arrest was of cardiac origin and 52 % had a shockable rhythm. In 74 % the cardiac arrest was witnessed, 76 % received bystander cardiopulmonary resuscitation and in 39 % an automatic external defibrillator (AED) was used. Of the 168 hospitalised patients, 144 underwent therapeutic procedures. A total of 105 patients survived until hospital discharge. Younger age, cardiac arrest in public area, witnessed cardiac arrest, cardiac origin with a shockable rhythm, the use of an AED, shorter time until return of spontaneous circulation, Glasgow Coma Scale (GCS) ≥13 during transport and longer length of hospital stay were associated with survival. Of the 105 survivors 72 survived for at least 1 year after cardiac arrest and 6 patients died.

Conclusion

A survival rate of 43 % after OHCA is achievable. Witnessed cardiac arrest, cardiac cause of arrest, initial cardiac rhythm and GCS ≥13 were associated with higher survival.     

Aborted sudden cardiac death in a 52-yearold man without structural heart disease

Sudden cardiac death in the absence of apparent structural heart disease is an uncommon phenomenon. The majority of these patients do not have ‘normal’ hearts and specific diagnostic tools are required to identify structural or functional abnormalities. We describe the history of a 50-yearold man who survived ventricular fibrillation. Clinical investigation, including a coronary angiography and electrophysiological study, appeared to be normal. An implantable cardioverter defibrillator was inserted. Follow-up Holter monitoring was performed after a recurrent episode of ventricular tachycardia. It demonstrated transient ST-segment elevation. An acetylcholine provocation test was subsequently carried out. Reversible coronary spasm of the left descending coronary artery was found, during which a diagonal branch was occluded. It may be concluded that coronary spasm provocation is of value in the routine diagnostic work-up of patients surviving sudden cardiac death without apparent heart disease. (Neth Heart J 2008;16:239-41.)     

Full pattern of transient apical ballooning of the left ventricle triggered by minor myocardial infarction

A 60-year-old female with a history of hypertension, hypercholesterolaemia, and diabetes mellitus presented two hours after sudden onset of severe persistent chest pain. Electrocardiography showed ST-segment elevation in the inferolateral leads (figure 1A). Coronary angiography revealed a subtotal occlusion of a small left marginal side branch (figure 1B; arrow) and a normal right coronary artery, which could not explain the full typical pattern of apical ballooning as demonstrated by left ventricular angiography (figure 1C and D; arrows).     

Coronary tortuosity: a long and winding road

Coronary tortuosity is a phenomenon often encountered by cardiologists performing coronary angiography. The aetiology and clinical importance of coronary tortuosity are still unclear. Coronary tortuosity without fixed atherosclerotic stenosis in patients with angina pectoris and an abnormal exercise stress test has never been described in the literature. This article describes three cases of patients with anginal complaints, an abnormal exercise stress test and coronary angiography without the presence of a fixed atherosclerotic lesion. It is hypothesised that coronary tortuosity leads to flow alteration resulting in a reduction in coronary pressure distal to the tortuous segment of the coronary artery, subsequently leading to ischaemia. Future studies will be necessary to elucidate the actual mechanism of coronary tortuosity and its clinical significance. (Neth Heart J 2007;15:191-5.)     

Early and long-term outcome of elective stenting of the infarct-related artery in patients with viability in the infarct-area: Rationale and design of the Viability-guided Angioplasty after acute Myocardial Infarction-trial (The VIAMI-trial)

BACKGROUND: Although percutaneous coronary intervention (PCI) is becoming the standard therapy in ST-segment elevation myocardial infarction (STEMI), to date most patients, even in developed countries, are reperfused with intravenous thrombolysis or do not receive a reperfusion therapy at all. In the post-lysis period these patients are at high risk for recurrent ischemic events. Early identification of these patients is mandatory as this subgroup could possibly benefit from an angioplasty of the infarct-related artery.Since viability seems to be related to ischemic adverse events, we initiated a clinical trial to investigate the benefits of PCI with stenting of the infarct-related artery in patients with viability detected early after acute myocardial infarction. METHODS: The VIAMI-study is designed as a prospective, multicenter, randomized, controlled clinical trial. Patients who are hospitalized with an acute myocardial infarction and who did not have primary or rescue PCI, undergo viability testing by low-dose dobutamine echocardiography (LDDE) within 3 days of admission. Consequently, patients with demonstrated viability are randomized to an invasive or conservative strategy. In the invasive strategy patients undergo coronary angiography with the intention to perform PCI with stenting of the infarct-related coronary artery and concomitant use of abciximab. In the conservative group an ischemia-guided approach is adopted (standard optimal care).The primary end point is the composite of death from any cause, reinfarction and unstable angina during a follow-up period of three years. CONCLUSION: The primary objective of the VIAMI-trial is to demonstrate that angioplasty of the infarct-related coronary artery with stenting and concomitant use of abciximab results in a clinically important risk reduction of future cardiac events in patients with viability in the infarct-area, detected early after myocardial infarction.     

Long-term outcomes of a Caucasian cohort presenting with acute coronary syndrome and/or out-of-hospital cardiac arrest caused by coronary spasm

Background

Coronary artery spasm may be the underlying mechanism in up to 10% of cases of acute coronary syndrome (ACS) and sudden cardiac death. Asian individuals exhibit a 3-times greater incidence of spasm than Caucasians; this is likely due to different types of mechanisms. Consequently, solid data is limited about the long-term prognosis in Caucasian patients presenting with ACS and/or out-of-hospital cardiac arrest (OHCA) caused by coronary spasm.

Methods

Between 2002 and 2015, thirty Caucasian patients with coronary artery spasm presenting with ACS (N = 29) and/or OHCA (N = 11) were enrolled in this prospective registry. Follow-up, consisting of regular outpatient visits, was conducted with a mean follow-up period of 7.5 ± 3.3 years. Outcomes included presence of stable angina pectoris, recurrence of ACS, occurrence of implantable cardioverter defibrillator (ICD) shocks and death.

Results

The majority of patients (60%) remained asymptomatic during the entire follow-up period. At the end of the follow-up period only 3 patients still experienced stable angina (10%). Only 2 patients (7%) had a recurrent cardiac event, in which the ICD provided appropriate shock therapy. Half of the patients treated with stenting (N = 6), required re-interventions.

Conclusion

Coronary spasm with ACS and/or OHCA in a Caucasian patient cohort has a relatively benign prognosis in the majority of patients in long-term follow-up, if treated appropriately with medical therapy. Both the role of ICD in OHCA secondary to coronary spasm, and the efficacy of stenting to treat vasospastic angina, warrant further study in large-sized prospective clinical trials.

     

Left ventricular aneurysm in patients with idiopathic dilated cardiomyopathy: clinical analysis of six cases

Background. Left ventricular aneurysm (LVA) in patients with idiopathic dilated cardiomyopathy (IDCM) is rarely reported, and the incidence, pathogenesis and clinical features of LVA in IDCM are poorly understood. Methods. The diagnosis of IDCM with LVA formation was made in six patients between January 2003 and September 2008. Left ventriculography, coronary angiography, echocardiogram and electrocardiogram were performed in all patients. The hospital records of these patients with IDCM in our hospital and related literature were reviewed. Results. LVA was located at the posterobasal wall in five patients and at the anterolateral wall in one patient. Two patients had abnormal Q waves and no patients had sustained ST-segment elevation on electrocardiogram. No significant coronary stenosis or mural thrombi was detected in these patients. All patients had severe ventricular arrhythmia, such as frequent multifocal ventricular premature contractions and ventricular tachycardia. Conclusion. IDCM could be a rare cause of LVA. The LVA in IDCM was mainly located at the posterobasal wall. It was seldom accompanied by abnormal Q waves and sustained ST-segment elevation. The pathogenesis of LVA in IDCM seems to be less likely to be related to coronary emboli. Ventricular arrhythmia occurred frequently in these patients. (Neth Heart J 2009;17:475–80.)     

Home Care Providers to the Rescue: A Novel First-Responder Programme

AimTo describe the implementation of a novel first-responder programme in which home care providers equipped with automated external defibrillators (AEDs) were dispatched in parallel with existing emergency medical services in the event of a suspected out-of-hospital cardiac arrest (OHCA).MethodsWe evaluated a one-year prospective study that trained home care providers in performing cardiopulmonary resuscitation (CPR) and using an AED in cases of suspected OHCA. Data were collected from cardiac arrest case files, case files from each provider dispatch and a survey among dispatched providers. The study was conducted in a rural district in Denmark.ResultsHome care providers were dispatched to 28 of the 60 OHCAs that occurred in the study period. In ten cases the providers arrived before the ambulance service and subsequently performed CPR. AED analysis was executed in three cases and shock was delivered in one case. For 26 of the 28 cases, the cardiac arrest occurred in a private home. Ninety-five per cent of the providers who had been dispatched to a cardiac arrest reported feeling prepared for managing the initial resuscitation, including use of AED.ConclusionHome care providers are suited to act as first-responders in predominantly rural and residential districts. Future follow-up will allow further evaluation of home care provider arrivals and patient survival.     

Prognostic implications of changes in cardiac troponin I levels in patients with non-ST elevation acute coronary syndrome

Abstract

Objective: Information is limited on the prognostic implications of cardiac troponin I (cTnI) changes during the first days of non-ST elevation acute coronary syndrome (NSTE-ACS).

Methods: High-sensitivity cTnI levels were measured at study inclusion and after 48?h in 1615 conservatively managed NSTE-ACS patients from the Global Use of Strategies To Open Occluded Coronary Arteries (GUSTO) IV trial.

Results: Patients with moderately increased cTnI levels and without a relevant decrease over time had a significantly raised mortality at 30 days and 1 year. No relevant associations between cTnI changes and recurrent myocardial infarction were seen.

Conclusion: The cTnI change is predictive for subsequent mortality in selected conservatively managed NSTE-ACS patients.     

Role of prophylactic coronary revascularisation in improving cardiovascular outcomes during non-cardiac surgery: A narrative review

Coronary revascularisation has been a topic of debate for over three decades in patients undergoing high-risk non-cardiac surgery. The paradigm shifted from routine coronary angiography toward stress test guided decision-making based on larger randomised trials. However, this paradigm is challenged by relatively newer data where routine coronary angiography and revascularisation is shown to improve perioperative cardiovascular outcomes. We review major studies performed over a long period including more contemporary data with regard to the 2014 American College of Cardiology/American Heart Association as well as 2014 European Society of Cardiology guideline on perioperative cardiovascular evaluation of patients undergoing non-cardiac surgery.     

Attention needed for cognitive problems in patients after out-of-hospital cardiac arrest: an inventory about daily rehabilitation care

Aim

Recent literature and Dutch guidelines for patients with out-of-hospital cardiac arrest (OHCA) recommend screening for cognitive impairments and referral to cognitive rehabilitation when needed. The aim of this study is to assess the uptake of these recommendations for OHCA patients.

Method

An internet-based questionnaire was sent to 74 cardiologists and 143 rehabilitation specialists involved in rehabilitation of OHCA patients in the Netherlands. The questionnaire covered: background characteristics, availability and content of cognitive screening and rehabilitation, organisation of care, experienced need for an integrated care pathway including physical and cognitive rehabilitation, barriers and facilitators for an integrated care pathway.

Results

Forty-five questionnaires were returned (16 cardiologists and 29 rehabilitation doctors). Thirty-nine percent (n?=?17) prescribed cognitive screening. Eighty-nine percent underscores an added value of an integrated care pathway. Barriers for an integrated care pathway included lack of knowledge, logistic obstacles, and poor cooperation between medical specialties.

Conclusions

In the Netherlands, only a minority of cardiologists and rehabilitation specialists routinely prescribe some form of cognitive screening in OHCA patients, although the majority underscores the value of cognitive screening in OHCA patients in an integrated care pathway. The uptake of such a care pathway seems hindered by lack of knowledge and organisational barriers.

     

Circumstances and causes of sudden circulatory arrests in the Dutch province of Limburg and the involvement of citizen rescuers

Background

Recently we showed that a citizen volunteer system using text message alerts improves survival of out-of-hospital sudden circulatory arrest (OHCA). It is important to characterise the OHCA population encountered by the volunteers regarding circumstances and causes of the arrests.

Methods and Results

Eligible for this study were 968 OHCAs that occurred between April 2012 and April 2014 in the Dutch province of Limburg. The distribution of causes of OHCA, patient characteristics and resuscitation settings were compared between 492 arrests wherein volunteers were notified and 476 arrests where the dispatcher decided not to do so.In case of notification, the cause of OHCA was known in 345 cases and of cardiac origin (treatable) in 83.2% (287/345). About 41% of the cardiac arrests were caused by acute or chronic coronary artery disease. OHCA occurred within the home environment in about 84%. The OHCA was witnessed in 75% of the cases. In 60.9% of the cases a witness or bystander had already started basic life support. However, in approximately 18% of the OHCAs the volunteer was the first to start basic life support before arrival of the ambulance. In about 75% of the OHCAs the ambulance arrived at 6 minutes or later after time of notification by the dispatch centre.

Conclusion

The volunteer system is predominantly activated in situations for which it was developed; cases with cardiac aetiology (58%) and cases in the home environment (84%). The majority of patients encountered by the volunteers had ‘hearts too good to die’, underscoring the benefit of deploying citizen rescuers in programs to improve survival of OHCA.

     

Evaluation of hospital-based cardiac resuscitation, 1973-77

The resuscitation experience of a large teaching hospital during 1973-77 was reviewed. Resuscitation was attempted on 2091 victims of cardiac arrest; 261 patients (12.5%) survived to be discharged from hospital.Coronary heart disease caused about one half of all the cardiac arrests, but was associated with a better survival rate (14.4%) than the other causes. Cardiac arrest following multiple trauma had the worst prognosis; only 3% of the patients survived to be discharged from hospital. However, the main factor influencing outcome was the site of arrest. The survival rates of patients on whom resuscitation was initiated in the emergency room or an intensive care area were triple and double the rate for patients in hospital wards, although one third of all the cardiac arrests induced by a coronary event and occurring in hospital were on the wards. Patients whose arrest occurred outside hospital, where only basic life support was available, had a survival rate of just 6.3%, whereas those whose arrest occurred in the emergency room had a survival rate of 31.9%. Since these two patient groups were similar in terms of age and diagnosis, we believe that the potential survival rate for victims of cardiac arrest outside of hospital that are optimally treated is close to 30%.These data suggest that increased survival from cardiac arrest can be expected with extension of the resuscitation services both inside and outside of hospital, but particularly with increased emphasis on emergency cardiac care outside of hospital.     

Progressive epicardial coronary blood flow reduction fails to produce ST-segment depression at normal heart rates

ST-segment depression is commonly seen in patients with acute coronary syndromes. Most authors have attributed it to transient reductions in coronary blood flow due to nonocclusive thrombus formation on a disrupted atherosclerotic plaque and dynamic focal vasospasm at the site of coronary artery stenosis. However, ST-segment depression was never reproduced in classic animal models of coronary stenosis without the presence of tachycardia. We hypothesized that ST-segment depression occurring during acute coronary syndromes is not entirely explained by changes in epicardial coronary artery resistance and thus evaluated the effect of a slow, progressive epicardial coronary artery occlusion on the ECG and regional myocardial blood flow in anesthetized pigs. Slow, progressive occlusion over 72 min (SD 27) of the left anterior descending coronary artery in 20 anesthetized pigs led to a 90% decrease in coronary blood flow and the development of ST-segment elevation associated with homogeneous and transmural myocardial blood flow reductions, confirmed by microspheres and myocardial contrast echocardiography. ST-segment depression was not observed in any ECG lead before the development of ST-segment elevation. At normal heart rates, progressive epicardial stenosis of a coronary artery results in myocardial ischemia associated with homogeneous, transmural reduction in regional myocardial blood flow and ST-segment elevation, without preceding ST-segment depression. Thus, in coronary syndromes with ST-segment depression and predominant subendocardial ischemia, factors other than mere increases in epicardial coronary resistance must be invoked to explain the heterogeneous parietal distribution of flow and associated ECG changes.     

Detection of Tissue Factor Antigen and Coagulation Activity in Coronary Artery Thrombi Isolated from Patients with ST-Segment Elevation Acute Myocardial Infarction

Introduction

Although ruptured atherosclerotic plaques have been extensively analyzed, the composition of thrombi causing arterial occlusion in patients with ST-segment elevation acute myocardial infarction has been less thoroughly investigated. We sought to investigate whether coagulant active tissue factor can be retrieved in thrombi of patients with STEMI undergoing primary percutaneous coronary intervention.

Methods

Nineteen patients with ST-segment elevation acute myocardial infarction referred for primary percutaneous coronary intervention were enrolled in this study. Coronary thrombi aspirated from coronary arteries were routinely processed for paraffin embedding and histological evaluation (4 patients) or immediately snap frozen for evaluation of tissue factor activity using a modified aPTT test (15 patients). Immunoprecipitation followed by immunoblotting was also performed in 12 patients.

Results

Thrombi aspirated from coronary arteries showed large and irregular areas of tissue factor staining within platelet aggregates, and in close contact with inflammatory cells. Some platelet aggregates stained positive for tissue factor, whereas others did not. Monocytes consistently stained strongly for tissue factor, neutrophils had a more variable and irregular tissue factor staining, and red blood cells did not demonstrate staining for tissue factor. Median clotting time of plasma samples containing homogenized thrombi incubated with a monoclonal antibody that specifically inhibits tissue factor-mediated coagulation activity (mAb 5G9) were significantly longer than their respective controls (88.9 seconds versus 76.5 seconds, respectively; p<0.001). Tissue factor was also identified by immunoprecipitation in 10 patients, with significant variability among band intensities.

Conclusions

Active tissue factor is present in coronary artery thrombi of patients with ST-segment elevation acute myocardial infarction, suggesting that it contributes to activate the coagulation cascade ensuing in coronary thrombosis.     

Association between climate variables (cold and hot weathers,humidity, atmospheric pressures) with out-of-hospital cardiac arrests in Rasht,Iran

Climate change is one of the most important concerns for public health that affects communities and is a threat to human health. Few cross-sectional studies investigated the effects of extreme temperature as a risk factor on the cardiovascular system and the Out-of-Hospital Cardiac Arrests (OHCA).The current study aims to investigate the association between climate variables (cold and hot weathers, humidity, atmospheric pressures) with Out-of-Hospital Cardiac Arrests in Rasht, Iran.This is an ecological time-series study, which investigated 392 patients with OHCA that were hospitalized in Dr. Heshmat Medical center of Rasht city in a 3-years period. Data on meteorological variables were obtained from the General Meteorological Department of Guilan Province. Information regarding the number of cardiac arrest admissions was obtained from the sole specialized cardiac hospital of Rasht. Data were analyzed using R software.Hot weather decreases the number of cardiac attacks on the same day (lag 0), while the cold weather (relative risk (RR) = 1.408; confidence interval (CI): 1.014–1.955) increases the number of OHCA cases and unsuccessful cardiopulmonary resuscitation (CPRs). Low humidity (RR = 1.76; CI: 1.006–3.79) is associated with increased unsuccessful CPRs. High atmospheric pressures (RR = 1.166; CI: 1.001 to 1.787) are also associated with an increased number of cardiac arrest admissions. For women, men, and those aged >65 years of old, exposure with severe cold (RR = 1.335; CI: 1.014–1.758) and hot weathers, respectively, increases and decreases the number of cardiac arrest admissions.Cold weather has immediate impacts on the incidence of OHCA cases and unsuccessful CPRs. Decreasing humidity also increases the number of and decreases the success rate of CPRs. Increasing the awareness of patients with cardiovascular diseases (CVDs as well as improving the preparedness of emergency care teams can decrease the impacts of climate variables.