Association of normal body mass index and weight loss with long-term major cardiovascular events after PCI for myocardial infarction.

Objectives: To investigate whether normal body mass index (BMI) shortly after percutaneous coronary intervention (PCI) for myocardial infarction is associated with increased risk of long-term major cardiovascular events (MACE), and to explore potential clinical determinants of long-term weight loss (WL) after PCI. Methods: Single-center cohort study with 5-year follow-up of patients treated with PCI for myocardial infarction between 2016 and 2018. Categorical WL was defined as > 0 kg body weight reduction from baseline to end of follow-up. Results: Of 236 patients (24% women), mean age was 64.9 ± 10.2 years and mean BMI within 4 days after PCI was 27.1 ± 4.3 kg/m². Seventy-five patients (32%) had at least one MACE, equally distributed between those with normal weight (31%), overweight (32%), and obesity (31%). Patients with overweight or obesity had a lower crude mortality rate than their normal weight counterparts (7.4% vs 16.4%, p = 0.049), but the relative hazard of death did not differ from those with normal weight, HR 0.50, 95% CI 0.22-1.15. Patients with either a long-term WL (n = 112) or no WL (n = 95) had a comparable incidence of non-fatal MACE (27% vs 22%, p = 0.518). The proportion of patients reporting unintentional weight loss was significantly higher in the normal weight group (82%) compared with those with overweight (41%) or obesity (28%), p < 0.001. Conclusion: Our results did not confirm any association between normal BMI after PCI and long-term MACE. However, patients with normal BMI at baseline had a higher incidence of unintentional WL than those with elevated BMI. Trial registration: Current research information system in Norway (CRISTIN): ID 542528.