Upgrade to CRT yields volumetric benefits even for mild HF patients

Upgrading to cardiac resynchronization therapy (CRT) from right ventricular pacing (RVP) appears to be viable even for patients with mild heart failure (HF), leading to improved left ventricular (LV) volumetric responses and clinical outcomes, a recent study has found.

Researchers conducted a retrospective analysis of 58 mild HF patients on CRT. Twenty-seven (UG; mean age 64.8±13.1 years, 74 percent men) had previously been on RVP and were upgraded to CRT, while the remining 31 (DG; mean age 66.5±14.1 years, 77 percent men) had de novo CRT. The primary endpoint was a composite among total mortality, cardiac transplantation, and LV assist device implantation; other outcomes included HF hospitalization and ventricular tachyarrhythmia events.

After 6 months, LV end-systolic volume significantly dropped in both the UG (144.3±39.4 to 111.1±33.5 mL; p<0.01) and DG (134.5±36.6 to 123.5±45.6 mL; p=0.012) groups. However, only patients who had been upgraded to CRT saw a significant improvement in LV ejection fraction (31.7±6.8 percent to 39.7±8.5 percent; p<0.01); the 6-month change in DG was nonsignificant (p=0.15).

In terms of clinical examinations, a total of 21 composite endpoint events occurred over a median follow-up of 989 days, yielding an incidence rate of 36 percent. Twelve participants died from any cause, while five mortalities were due to cardiovascular reasons. Nine patients needed HF hospitalization, while 10 developed ventricular tachyarrhythmia.

The incidence rates of all clinical endpoints were comparable between the UG and DG groups, as was the cumulative survival rate at 2 years (p=0.18).

“Conclusively, our study demonstrated that the CRT upgrade in mild HF patients with midrange ejection fraction may be of benefit to achieve mechanical responses to CRT,” the researchers said.