1Universitätsklinikum Mannheim I. Medizinische Klinik Mannheim, Deutschland; 2Herz- und Diabeteszentrum NRW Allgemeine und Interventionelle Kardiologie/Angiologie Bad Oeynhausen, Deutschland; 3MediClin Herzzentrum Lahr/Baden Innere Medizin und Kardiologie Lahr/Schwarzwald, Deutschland; 4Medizinische Hochschule Hannover Kardiologie und Angiologie Hannover, Deutschland
Objective: The study investigates the prognostic value of body mass index (BMI) in a cohort of patients undergoing invasive coronary angiography (CA). Additionally, procedural data and outcomes were examined.
Background: Demographic changes and improved treatment strategies for patients with cardiovascular disease have significantly impacted the spectrum of patients undergoing CA over the past decades. Limited data regarding the characteristics and outcomes in unselected patients undergoing CA stratified by BMI is available.
Methods: Consecutive patients undergoing invasive CA from 2016 to 2022 were included at one institution. Patients were stratified by BMI on admission according to the current WHO definition and patients with a BMI 18.5 - <25 kg/m2, 25 - <30 kg/m2, 30 - < 35 kg/m2 and ≥ 35 kg/m2 were investigated. Firstly, the prevalence and extent of CAD, as well as procedural-related data was assessed. Secondly, the prognosis of BMI in patients undergoing CA was investigated with regard to the primary endpoint in-hospital all-cause mortality at 30 days. Secondary endpoints comprised the risk of acute myocardial infarction (AMI), revascularization and hospitalization for heart failure at 36 months of follow-up. Statistical analyses included Kaplan-Meier analyses, as well as uni- and multivariable Cox proportional regression analyses.
Results: From 2016 to 2022, 6,583 patients undergoing CA were included with a median BMI of 27.4 kg/m2 (mean BMI: 28.2 kg/m2). Patients with a BMI of 25 - <30 kg/m2 had the highest prevalence of CAD (71.1% vs 69.2%, 69.8% and 61.4%; p = 0.001) as well as the highest prevalence of 3-vessel CAD compared to patients in other BMI groups (30.5% vs. 29.2%, 28.9% and 20.1%; p = 0.001), alongside with higher rates of percutaneous coronary intervention (PCI) (45.2% vs 41.0%, 43.0% and 35.6%; p = 0.001). A higher BMI was associated with a lower risk of 30-day in-hospital all-cause mortality (i.e. BMI 30 - < 35 kg/m2: HR = 0.432; 95% CI 0.261 – 0.714; p = 0.001; 25 - < 30 kg/m2: HR = 0.644; 95% CI 0.457 – 0.908; p = 0.012). After multivariable adjustment, the lowest risk of 30-day all-cause mortality was observed in patients with a BMI 30 - < 35 kg/m2 (HR = 0.656; 95% CI 0.438 – 0.984; p = 0.042), whereas higher BMI values were no longer associated with prognosis in patients undergoing CA.
Conclusion: Patients with a BMI 30 - < 35 kg/m2 were associated with the lowest risk of in-hospital all-cause mortality at 30-days, suggesting an obesity paradox in unselected patients undergoing CA.