After revascularization procedures, the risk for total mortality, CV mortality and MI is highest among patients with low BMI, according to research published in Mayo Clinic Proceedings.
Similarly, CV mortality was lowest among overweight patients in the meta-analysis conducted by Abhishek Sharma, MD, of the Maimonides Medical Center, Brooklyn, N.Y., and colleagues, who looked at PCI and CABG studies.
“Obesity has been considered a risk factor for worst clinical outcomes following CV procedures like PCI and CABG,” Sharma told Endocrine Today. “However, our results suggest that higher BMI has a protective effect after coronary revascularization procedures.”
The researchers reviewed 36 studies — 12 CABG and 26 PCI — from a search of databases that identified those specifically reporting MI, CV mortality and total mortality among patients with coronary artery disease post-procedures by BMI.
The rates were reported in categories of BMI: <20 kg/m2 (underweight), ≥20 kg/m2 and ≤24.9 kg/m2 (normal reference), ≥25 kg/m2 and ≤29.9 kg/m2 (overweight), ≥30 kg/m2 and ≤34.9 kg/m2 (obese) and ≥35 kg/m2 (severely obese). The team compared data using a random effects model, assuming heterogeneity between studies.
Patients with low BMI at follow-up (mean, 1.7 years) had the highest risk for total mortality (RR=2.59; 95% CI, 2.09-3.21), CV mortality (RR=2.67; 1.63-4.39) and MI (RR=1.79; 1.28-2.5).
Overweight patients had the lowest risk for CV mortality (RR=0.81; 95% CI, 0.68-0.95). Increased adiposity based on BMI had a neutral effect on MI risk for patients categorized as overweight (RR=0.92; 0.84-1.01), obese (RR=0.99; 0.85-1.15) and severely obese (RR=0.93; 0.78-1.11).
“At this stage we can only speculate on the reasons for this paradox,” Sharma said in a press release.
Among the possible explanations Sharma cited are cardio-protective medications, favorable outcomes from large coronary vessel damage, higher metabolic reserve, varied pathophysiology of CV disease and non-modifiable genetic predisposition.
Further studies are underway to investigate the existence of such paradox in various CVDs and patient populations, Sharma said in an interview.
“We will also investigate this association and explore potential underlying mechanisms in upcoming prospective studies,” Sharma said. — by Allegra Tiver.
Disclosure: One researcher reports support from a Victoria and Esther Aboodi Assistant Professorship.