P5552Protective effect of obesity in acute myocardial infarction: evidence of the “obesity paradox”

Introduction: Obesity has been suggested as a protective factor in several chronic pathologies, namely in heart failure. Some evidence suggests that low-grade chronic inflammation, as in obesity, can protect heart against acute inflammation and ischemia. However, the impact of the obesity paradox in AMI is still matter of debate. Aim: Evaluation of prognostic value of body mass índex (BMI) on in-hospital cardiovascular mortality in patients admitted with AMI. Methods: We retrospectively analyzed 2178 patients who were admitted to our coronary care unit with AMI. Three groups were created based on BMI: i) normal (N; IMC<25 kg/m2); ii) overweight (Ow; ≥25 IMC <30 kg/m2); iii) obesity (Ob; IMC≥30 kg/m2). Clinical and laboratory features, treatment and adverse events were compared between groups. The primary outcome was in-hospital cardiovascular death (IH-CVD). Results: We observed an inverse association between BMI and age (N 65.1±14.2; Ow 64.3±12.9; Ob 62.1±12.7 years; p<0.001) and a direct association with main cardiovascular risk factors, namely diabetes mellitus (N 18.2; Ow 28.3; Ob 34.6%; p<0.001), hypertension (N 55.3; Ow 66.2; Ob 67.7%; p<0.001) and dyslipidemia (N 47.9; Ow 58.2; Ob 59.7%; p<0.001), with a predominance of male gender in all groups (N 73.2; EP 81.5; Ob 75.9%; p<0.001). At admission, no differences were observed regarding hemodynamic parameters (blood pressure, heart rate and left ventricle ejection fraction) or clinical presentation (Killip class). Patients with lower BMI presented more often with STEMI (N 52.3; Ow 48.2; Ob 42.5%; p<0.001), while no differences were observed regarding multivessel disease or revascularization rate. Regarding analytical data, BMI was positively associated with plasma triglycerides (N 135.5±86.5; Ow 161.6±108.8; Ob 183.1±133.1mg/dL; p<0.001) and negatively associated with NT-proBNP (N 3716±7415; Ow 2669±5147; Ob 2593±5931pg/mL; p=0.0015) with no differences observed in total cholesterol, LDL, hemoglobin, renal function, peak troponin I and C-reactive protein. Obesity was associated with lower incidence in-hospital adverse events, namely cardiogenic shock (N 6.6; EP 4.7 Ob 3.8%; p<0.04), stroke (N 1.8; EP 0.5; Ob 0.5%; p<0.005) and need for aminergic support (N 8.4; Ow 5.9; Ob 5.2%; p<0.02). The in-hospital cardiovascular mortality was inferior in obese group (N 4.4; Ow 2.6; Ob 1.9%; p=0.0285). In fact, an inverse association was detect between BMI and in-hospital CV mortality (OR 0.91; 95% CI 0.87–0.95, p<0.001), which remained significant in multivariate analysis, after adjustment for important predictors of CV mortality, namely age, gender, DM, HTA, peak troponin I, STEMI, eGFR and Hb (OR 0.91; 95% CI 0.86–0.97, p=0.006).