DefinePK

Abstract

The burden of acute coronary syndrome (ACS) in South Asia remains unacceptably high, with Pakistan facing an alarming increase in premature coronary events, particularly among younger individuals with multiple comorbidities [1,2]. In this context, the prospective study by Shah et al., conducted at the National Institute of Cardiovascular Diseases (NICVD), provides valuable insight into one of the most complex and high-risk clinical scenarios: patients who survive sudden cardiac arrest (SCA) secondary to ACS [3].
This single-center observational study of 97 patients reflects both the growing clinical capabilities and the evolving infrastructure of cardiovascular care in Pakistan. The authors report that aggressive management strategies—including early coronary angiography and percutaneous coronary intervention (PCI)—were associated with favorable in-hospital survival in a significant proportion of these critically ill patients. In doing so, they underscore the feasibility and impact of high-intensity interventions in a low- and middle-income country (LMIC) setting.
Sudden cardiac death (SCD) accounts for nearly half of all cardiovascular-related mortality worldwide, and while high-income countries have made significant advances in its management, data from LMICs remain scarce [4-6]. Shah et al.’s study contributes important regional evidence by stratifying outcomes based on arrhythmic subtype and presenting detailed angiographic profiles and procedural outcomes. Notably, tachyarrhythmias were the most frequent presenting rhythm, observed in over 55% of cases. This reinforces the need for protocol-driven resuscitation and rapid rhythm control strategies tailored to the local population.
Furthermore, the study found that approximately 43% of patients had severely reduced left ventricular ejection fraction (≤35%), and nearly half had complex coronary lesions, including American Heart Association (AHA) type C anatomies. These findings highlight the procedural challenges inherent in this patient cohort and emphasize the need for advanced interventional expertise and catheterization laboratory support. Remarkably, despite the high-risk clinical profile—24.7% were in Killip Class III or IV and many developed multi-organ complications—the in-hospital mortality rate was limited to 10.3%, illustrating the potential life-saving impact of aggressive early revascularization and comprehensive post-resuscitation care.
Importantly, no independent predictors of mortality were identified on multivariable logistic regression analysis, pointing to a multifactorial interplay of anatomical, hemodynamic, and logistical elements. Nevertheless, prior myocardial infarction and Killip Class IV status emerged as variables of interest, meriting further exploration in larger cohorts.
The study’s findings also illuminate a major gap in current practice: the absence of validated prognostic tools for risk stratification in this high-risk population. Developing such tools—incorporating clinical, procedural, and laboratory variables—could guide decision-making and improve both survival and neurological outcomes in post-SCA ACS patients.
Resource constraints, delayed presentations, and fragmented referral systems remain major barriers to implementing aggressive management across most public-sector hospitals in Pakistan. In this context, the study represents not only a clinical achievement but also a systems-level success. Scaling this model across secondary and tertiary centers will require targeted investments, including advanced cardiac life support (ACLS) training, 24/7 PCI availability, structured post-resuscitation care protocols, and dedicated follow-up services for survivors—especially those with neurological impairment.
Looking ahead, the authors’ call for a case-control study comparing aggressive versus conservative management is appropriate and timely. Future studies should include long-term follow-up data on neurological function, quality of life, and cost-effectiveness. National bodies such as the Pakistan Cardiac Society (PCS) could play a pivotal role by convening expert consensus to develop standardized guidelines for post-resuscitation ACS care in resource-limited settings. Adaptation of models like the U.S.-based Cardiac Arrest Centers or Europe’s Cardiac Arrest Survivorship Network (CASN) should be considered, with careful contextual tailoring.
While this study offers significant insights, certain methodological aspects warrant clarification. The authors do not specify whether all cardiac arrests were witnessed or if rhythm documentation was uniformly performed—details critical for accurate classification. The timing of rhythm identification (pre-arrest, intra-arrest, or post-resuscitation) also remains unclear, potentially affecting the interpretation of arrhythmic subtypes. The emphasis on post-CPR rhythms may be overstated in cases lacking clear electrophysiological or conduction system pathology. Clarifying how many patients required pacing would help distinguish true bradyarrhythmias from agonal or terminal rhythms. Moreover, the omission of data on bystander cardiopulmonary resuscitation (CPR)—especially hands-only CPR, now widely promoted for lay responders in LMICs—represents a missed opportunity to advocate for improved prehospital care and community training programs.
This study is a commendable example of pragmatic, outcomes-focused research addressing a neglected yet vital area of cardiovascular care. It demonstrates that survival after ACS-related cardiac arrest is not only possible but increasingly likely with timely, aggressive, and well-coordinated interventions—even in resource-limited settings. The findings reinforce the imperative to expand and systematize such models of care across Pakistan and other LMICs, translating clinical evidence into broader health system reforms.
References

Huikuri HV, Castellanos A, Myerburg RJ. Sudden death due to cardiac arrhythmias. N Engl J Med. 2001;345(20):1473-82. DOI: 10.1056/nejmra000650
Solomon SD, Zelenkofske S, McMurray JJ, Finn PV, Velazquez E, Ertl G, et al. Sudden death in patients with myocardial infarction and left ventricular dysfunction, heart failure, or both. N Engl J Med. 2005;352(25):2581-8. DOI: 10.1056/nejmoa043938
Shah AA, Jalbani J, Shah SDA, Khan MS, Wahid A, Khan I, Saghir T, Ammar A. Outcomes of Aggressive Management in Acute Coronary Syndrome Patients Surviving Sudden Cardiac Arrest. Pak Heart J. 2025;58(02):214-221. DOI: 10.47144/phj.v58i2.2821
Zipes DP, Wellens HJ. Sudden cardiac death. Circulation. 1998;98(21):2334-51. DOI: 10.1161/01.cir.98.21.2334
Waks JW, Buxton AE. Risk Stratification for Sudden Cardiac Death After Myocardial Infarction. Annu Rev Med. 2018;69:147-64. DOI: 10.1146/annurev-med-041316-090046
Zipes DP, Wellens HJ. Sudden cardiac death. Circulation. 1998;98(21):2334-51. DOI: 10.1161/01.cir.98.21.2334