In-hospital and 1-year outcomes of patients without modifiable risk factors presenting with acute coronary syndrome undergoing PCI: a sex-stratified analysis
Authors: Fallahzadeh A , Sheikhy A , Jameie M , Aein A , Masoudkabir F , Tajdini M , Salarifar M , Jenab Y , Pourhosseini H , Mehrani M , Alidoosti M , Hosseini K , Sarraf M 
Published: November 2023

Abstract

Background
The standard modifiable cardiovascular risk factors (SMuRFs: hypertension, diabetes mellitus, dyslipidemia, and cigarette smoking) are known to play a major role in the pathogenesis of coronary heart disease (CHD). Despite endeavors aiming at primary and secondary prevention of these risk factors, CHD has remained a leading cause of mortality and morbidity worldwide. A considerable proportion of patients admitted with acute coronary syndrome (ACS) have no SMuRFs, the outcomes of whom following percutaneous coronary intervention (PCI) are debated. Further, sex differences within this population have yet to be established.

Purpose
The present study aimed to evaluate the association between SMuRF-less status and post-PCI outcomes among patients with ACS. Further, we sought to determine possible sex differences in the post-PCI outcomes related to the SMuRF-less status.

Methods
This retrospective cohort study included 7847 patients with ACS who underwent PCI. The study outcomes were all-cause mortality and major adverse cardio-cerebrovascular events (MACCE). The association between the absence of SMuRFs (SMuRF-less status) and outcomes among all the patients and each sex was assessed using logistic and Cox proportional hazard regressions. A separate landmark analysis with the landmark (cutoff) set at 30 days after the index procedure was performed as well. Models were adjusted for age, sex, body mass index, chronic obstructive pulmonary disease, cerebrovascular accident, previous myocardial infarction, estimated glomerular filtration rate, ejection fraction, and left main disease.

Results
Approximately 11% of the study population had none of the SMuRFs. The SMuRF-less and SMuRF+ groups aged 63.10 ±8.91 (85.1% males) and 62.53 ± 10.91 years (74.9% males), respectively. During 12.13 [11.99-12.36] months of follow-up, the followings were respective event numbers in the SMuRF-less and SMuRF+ groups: all-cause mortality: 35 (4.1%) and 273 (3.9%); MACCE: 99 (11.6%) and 898 (12.8%). All-cause mortality (adjusted-hazard ratio (HR): 1.01, 95%CI: 0.88-1.46, P: 0.731), and MACCE (adjusted-HR: 0.93, 95%CI:0.81-1.12, P: 0.412) did not differ between patients with and without SMuRFs (Figure 1). Sex-stratified analyses recapitulated similar outcomes between SMuRF+ and SMuRF-less men. In contrast, SMuRF-less women had significantly higher all-cause mortality (adjusted-HR:1.41, 95%CI: 1.02-3.21, P: 0.008) than SMuRF+ women (Figure 1). Notably, following landmark analyses, this significant association among women disappeared (adjusted-HR: 0.99, 95%CI: 0.41-2.59, P:0.991), implying that its significance stemmed, to some extent, from higher 30-day mortality (Figure 1,2).

Conclusions
Almost one in 10 patients with ACS who underwent PCI had no SMuRFs. The absence of SMuRFs did not confer any benefit in terms of in-hospital mortality, one-year mortality, and MACCE. Even worse, SMuRF-less women paradoxically had an excessive risk of one-year mortality.