The "overweight paradox" in the prognosis of acute coronary syndrome for patients with heart failure-A truth for all? A 10-year follow-up study

Objectives: In established acute coronary syndrome (ACS) with major complications (i.e. heart failure), overweight/obese patients usually have a survival advantage. To what extent this is irrespective of other characteristics remains inconclusive. The role of body mass index (BMI) in ACS prognosis (fatal/recurrent non-fatal cardiac episodes) and background potential interactions were evaluated.

Study design: In 2006-2009, 1000 consecutive patients, hospitalized at First Cardiology Clinic of Athens with a diagnosis of ACS were enrolled in the study. All patients were classified according to heart failure phenotypes. One-month, 1-, 2- and 10-year follow-up examinations were performed (75% participation rate).

Main outcome measures: Overweight was defined as 25≤BMI≤29.9kg/m2 and obesity as BMI >29.9kg/m2.

Results: BMI status and 10-year ACS prognosis followed a J-shape association (p=0.009). Overweight patients had significantly better ACS prognosis than their normal-weight counterparts (OR=0.45, 95% CI (0.23, 0.90)). Significant interactions were observed between sociodemographic, clinical and lifestyle parameters and BMI on 10-year ACS prognosis (all ps for interaction≤10%); the aforementioned paradoxical association was retained only in patients who: were female (OR=0.37, 95% CI (0.16, 0.82)); were aged ≤65 years (OR=0.25, 95% CI (0.09, 0.69)), HFrEF (OR=0.35, 95% CI (0.13, 0.89)); were hypercholesterolemic (OR=0.23, 95% CI (0.07, 0.81)); had no hypertension (OR=0.31, 95% CI (0.12, 0.82)) or diabetes mellitus (OR=0.29, 95% CI (0.09, 0.95)); had moderate/high adherence to a Mediterranean diet (OR=0.43, 95% CI (0.22, 0.86)); and were physically active (OR=0.37, 95% CI (0.15, 0.88)).

Conclusions: Although the overweight paradox was observed in the 10-year ACS prognosis of heart failure patients, this paradoxical association was not the case for all.