Inpatient vs. elective outpatient cardiac resynchronization therapy device implantation and long-term clinical outcome

It remains unclear whether cardiac resynchronization therapy (CRT) device implantation during inpatient (IP) hospitalization affords the same benefit as elective outpatient (OP) implantation. We hypothesized that IPs undergoing CRT device implantation during acute hospitalization may have worse outcomes compared with elective OP implantation. We retrospectively separated patients undergoing CRT implants at Massachusetts General Hospital into OP (n= 196) and IP (n = 105) cohorts. Long-term outcomes, measured as heart failure (HF) hospitalization, all-cause mortality, ventricular assist device placement, or heart transplant over a 2-year follow-up period, were estimated by the Kaplan-Meier method. Propensity scores were generated to balance the baseline co-morbidities between IP and OP. Baseline age, gender, left ventricular ejection fraction, and aetiology of cardiomyopathy were comparable between OP and IP (66.8 +/- 11.8 vs. 67.5 +/- 13.4 years, 78 vs. 84% males, 24 vs. 23%, and 39 vs. 50% ischaemic, P = NS). Inpatients had greater burden of diabetes mellitus (40 vs. 27%, P = 0.028), renal insufficiency (47 vs. 25%, P < 0.001), and right ventricular dysfunction (54 vs. 39%, P = 0.026) compared with OPs. At 2-year follow-up, IP implant was associated with greater risk of HF hospitalization (HR 1.6, 95% CI 1.03-2.48, P = 0.038) compared with elective OP implants. After propensity score adjustment, there was no statistically significant difference in HF hospitalization between the IP and OP groups (HR 1.031, 95% CI 0.61-1.78, P = 0.91). Compared with OP CRT implants, IPs are at increased risk for recurrent HF hospitalization; however, the increased risk is attributable to greater co-morbidities in the IP population.