Underweight is Associated with Inferior Short and Long-term Outcomes After MitraClip Implantation: Results from the German TRAnscatheter Mitral Valve Interventions (TRAMI) Registry

Background: Underweight and obesity represent classical risk factors for adverse outcome in patients treated for cardiovascular disease.

Aims: The current analysis examines the impact of underweight, overweight and obesity on intra-hospital, short and long-term outcomes in patients treated by MitraClip therapy.

Methods And Results: From August 2010 until July 2013, 799 patients (age 75.3 ± 8.6 years, male gender 60.7%, median logistic EuroSCORE 20% [12; 31], functional mitral regurgitation (MR): 69.3%) were prospectively enrolled into the multicenter German Transcatheter Mitral Valve Interventions registry. Patients were stratified according to body mass index (BMI) into 4 groups: BMI <20 kg/m (underweight), BMI 20.0 to <25.0 kg/m (normal weight, reference group), BMI 25.0 to <30.0 kg/m (overweight) and BMI ≥30 kg/m (obese). Significant increased rates of procedural failure, transfusion/bleeding, sepsis or multiorgan failure and low cardiac output failure were found for underweight patients only. Kaplan-Meier survival curves demonstrated inferior survival for underweight patients, but comparable outcomes for all other patients (global log rank test, P < .01). Multivariable Cox-regression analysis (adjusted for age, gender, creatinine ≥1.5 mg/dL, diabetes, left ventricular ejection fraction <30% and chronic obstructive pulmonary disease) confirmed underweight (as compared to normal weight) as an independent risk factor of death (hazard ratio [HR]: 1.58, 95% confidence interval (CI): 1.01-2.46, P = .044) and overweight as protective against death (HR: 0.71; 95%-CI: 0.55-0.93; P = .011).

Conclusions: Compared to other weight groups, underweight patients undergoing MitraClip implantation are exposed to increased rates of procedural failure, bleeding and low cardiac output as well as increased short- and long-term mortality rates and should therefore be carefully discussed in the heart-team.