Temporal trends in the contribution of modifiable cardiovascular risk factors to cardiovascular and all-cause mortality in patients undergoing myocardial perfusion imaging in a large city in Brazil

Background: Most cardiovascular (CV) events stem from modifiable risk factors, but it remains uncertain whether their impact on mortality has decreased in recent years as a result of treatment, particularly in low- and middleincome countries. We evaluated the temporal trends in the population attributable fraction (PAF) of modifiable risk factors to CV mortality in patients undergoing myocardial perfusion imaging (MPI) for suspected coronary artery disease in a large city in Brazil. Methods: The cohort comprised 25,127 patients without established CV disease undergoing MPI in a referral center in Curitiba, Brazil, from 2010 to 2018. Baseline demographic, clinical and risk factors were prospectively collected. Modifiable risk factors encompassed hypertension, dyslipidemia, diabetes mellitus, sedentary lifestyle, obesity, and smoking. The primary outcome was CV death occurring up to 4 years of follow-up. The PAF of each risk factor was calculated for each triennium using multivariable Cox proportional regression models, adjusting for age, sex and family history of premature coronary disease. Results: Over 9 years, there were 1438 deaths, 444 due to CV causes. In the first triennium, sedentary lifestyle exhibited the highest PAF (49%) for CV death, followed by hypertension (17%), diabetes mellitus (8%) and smoking habit (6%). The PAF for all risk factors combined remained relatively stable thorough the triennia (2010 -2012: 57% vs 2013 -2015: 64% vs 2016 -2018: 47%, p = NS). Conclusion: In this large cohort of patients referred to MPI, the PAF of modifiable CV risk factors did not diminish in the last decade, with sedentary lifestyle having the largest contribution for CV mortality. Condensed abstract: This study examinated temporal trends in the impact of modifiable cardiovascular (CV) risk factors on CV and overall mortality in a cohort of 25,127 patients undergoing myocardial perfusion imaging from 2010 to 2018. Sedentary behavior consistently had the greatest impact on both CV and overall mortality, followed by hypertension and diabetes. Smoking had a lesser effect, while obesity showed no independent association with the outcomes. The contributions of these modifiable CV risk factors remained stable over the study period, suggesting that interventions promoting physical activity may be essential in mitigating the burden of CV disease.