Association of body mass index with cardiac resynchronization therapy intention and left ventricular lead implantation failure: insights from the NCDR implantable cardioverter-defibrillator registry.

BACKGROUND

Cardiac resynchronization therapy with defibrillator (CRT-D) implantation involves left ventricular (LV) lead placement for biventricular pacing and is more complex than implantable cardioverter-defibrillator (ICD)-only implantation. Differences in the prescription of CRT-D versus ICD may result from clinician biases based on patient body habitus, and body habitus may be associated with LV lead implantation failure.

OBJECTIVE

We sought to evaluate whether patient body mass index (BMI) was associated with planned use and implantation failure of CRT-D therapy.

METHODS

We studied all patients enrolled in the National Cardiovascular Data Registry ICD Registry who met standard CRT-D criteria and received either an ICD or CRT-D between 2010 and 2012. BMI was categorized based on World Health Organization classification. Using hierarchical logistic regression, two multivariate models adjusted for patient demographic and clinical characteristics were fit based on the following outcome variables: (1) planned implantation with CRT-D versus ICD and (2) failed versus successful LV lead placement.

RESULTS

Of 337,547 patients, 41,872 met inclusion criteria for the first analysis and 35,186 met criteria for the second analysis. After multivariable adjustment, patients with extreme (BMI > 40 kg/m2) obesity were less likely to receive guideline-concordant CRT-D compared with patients with normal weight (adjusted odds ratio (AOR), 0.86; 95% confidence interval (CI), 0.75-0.99; p = 0.04). Extreme (BMI > 40 kg/m2) obesity was associated with higher odds of failed LV lead placement (AOR, 1.35; 95% CI, 1.07-1.72, p = 0.01).

CONCLUSIONS

Compared with normal weight patients, extremely obese (BMI > 40 kg/m2) CRT-D eligible patients were less likely to be prescribed CRT-D and were at higher odds for failed LV lead placement.