Clinical characteristics, management, and 5-year survival compared between no standard modifiable risk factor (SMuRFless) and ≥ 1 SMuRF ACS cases: an analysis of 15,051 cases from Pakistan

Abstract

Background There has been an increase in Acute Coronary Syndrome (ACS) patients without standard modifiable risk factors i.e. hypertension, diabetes, dyslipidemia, and tobacco use (SMuRFless) compared to the patients with ≥ 1 SMuRF but this has not been studied in South Asia despite them being a high-risk population. We conducted a comparative analysis of first episodes of ACS cases admitted to a tertiary cardiac center in Pakistan between SMuRFless and ≥ 1 SMuRF patients for clinical presentation, management, in-hospital, and 5-year mortality. Methods We undertook a retrospective study and data of 15,051 patients admitted at Tabba Heart Institute (THI) with the first episode of ACS was extracted from Chest Pain-MI™, and the CathPCI Registry® registry affiliated with the National Cardiovascular Data Registry (NCDR®), USA. Logistic regression and Cox proportional algorithm yielded odds ratio (OR) and hazard ratios (HR) with 95% confidence interval (CI) for associated factors of in-patient and 5-year mortality. Results There were 15% SMuRFless cases and in-hospital mortality was 4.1% in SMuRFless vs. 3.9% in the ≥ 1 SMuRF group (p-0.59), the difference remained insignificant after adjusting for age, gender, Killip class, multivessel disease, type of ACS, percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) (Adjusted OR:1.1 [0.8, 1.3]. Unadjusted 5-year mortality was 40% lower in the SMuRFless group but the difference was insignificant after adjusting for age, gender, disease at presentation, its severity, and management (Adjusted HR 0.7 95% CI[0.5, 1.0]). STEMI, NSTEMI, Killip class, and multivessel disease increased the risk of overall 5-year mortality. Conclusion In-hospital and 5-year mortality was not different between the SMuRFless and ≥ 1 SMuRF group, there is a need to understand mediators of immediate and long-term mortality risk in SMuRFless patients.

Patients With STEMI Without Standard Modifiable Risk Factors

“…Diversity in cardiovascular research is crucial because the lack of minority representation may lead to underestimated risks in non-White (refers to individuals who are not of Caucasian or European descent) groups. The observed increase in SMuRF-less STEMI patients from 11% to 27% over 8 years at a single Australian institution, 3 which was confirmed in a national cohort study, along with the findings of Sheikh et al 2 that 15% of acute coronary syndrome patients lacked SMuRFs point to evolving coronary artery disease risk profiles across populations.…”

“…South Asians present with STEMI at a younger age and with fewer SMuRFs, indicating a higher inherent risk of coronary disease. 2 The SWEDEHEART (Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies) is a comprehensive registry aimed at supporting the improvement of care and evidence-based development of therapies for coronary artery disease in Sweden. The SWEDEHEART registry shows a 19% 30-day mortality rate in SMuRF-less women with STEMI, significantly higher than SMuRF-presenting counterparts (11%; P < 0.0001).…”

“…The review by Zhao et al 1 emphasizes suboptimal adherence to guideline-directed therapies, contributing to heightened early mortality. Sheikh et al 2 showed that SMuRF-less patients had cardiac arrhythmia and STEMI at presentation, requiring more emergency percutaneous coronary intervention and highlighting the need for tailored management strategies.…”

In-hospital and 1-year outcomes of patients without modifiable risk factors presenting with acute coronary syndrome undergoing PCI: a Sex-stratified analysis

“…Notably, the association between the SMuRF-less status and considerable early mortality might be mediated through increased in-hospital complications, such as increased cardiogenic shock ( 21 ) and acute kidney injury ( 36 ). Different ACS presentations in the SMuRF-less population can also justify their not-reduced risk of adverse events as they are more likely to present with STEMI than patients with conventional risk factors ( 37 ).…”

Defining Outcomes in East Asian Elderly STEMI Patients Without Standard Modifiable Risk Factors

“…In conclusion, much remains to be elucidated in SMuRFless patients presenting with ACS, and careful attention is needed to understand regional and ethnic differences in outcomes from international cohorts, with attempts to clarify the factors driving these differences. The Chinese study 4 in this issue of JACC: Asia adds to an expanding global literature with prior SMuRFless cohorts reported from Japan, 7 India, 8 Pakistan, 9 Singapore, 10 Australia, 11 the United Kingdom, 12 Sweden, 1 and the United States, 13 and emphasizes the importance of recognizing the potential difference in outcome in SMuRFless patients of different age groups.…”