Impact of Modifiable Cardiovascular Risk Factors on Mortality After Percutaneous Coronary Intervention: A Systematic Review and Meta-Analysis of 100 Studies

Modifiable cardiovascular risk factors such as obesity, hypertension, dyslipidemia, smoking, diabetes mellitus, and metabolic syndrome can easily give rise to coronary heart disease (CHD). However, due to the existence of the so-called “obesity paradox” and “smoking paradox,” the impact of these modifiable cardiovascular risk factors on mortality after percutaneous coronary intervention (PCI) is still not clear. Therefore, in order to solve this issue, we aim to compare mortality between patients with low and high modifiable cardiovascular risk factors after PCI. Medline and EMBASE were searched for studies related to these modifiable cardiovascular risk factors. Reported outcome was all-cause mortality after PCI. Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated, and the pooled analyses were performed with RevMan 5.3 software. A total of 100 studies consisting of 884,190 patients (330,068 and 514,122 with high and low cardiovascular risk factors respectively) have been included in this meta-analysis. Diabetes mellitus was associated with a significantly higher short and long-term mortality with RR 2.11; 95% CI: (1.91–2.33) and 1.85; 95% CI: (1.66–2.06), respectively, after PCI. A significantly higher long-term mortality in the hypertensive and metabolic syndrome patients with RR 1.45; 95% CI: (1.24–1.69) and RR 1.29; 95% CI: (1.11–1.51), respectively, has also been observed. However, an unexpectedly, significantly lower mortality risk was observed among the smokers and obese patients. Certain modifiable cardiovascular risk subgroups had a significantly higher impact on mortality after PCI. However, mortality among the obese patients and the smokers showed an unexpected paradox after coronary intervention.