Left ventricular volume change and long-term outcomes in ischaemic cardiomyopathy with or without surgical revascularisation: A post-hoc analysis of a randomised controlled trial.

Background: Whether the association between post-therapeutic left ventricular volume change and long-term outcomes in ischaemic cardiomyopathy is influenced by the performance of coronary artery bypass grafting (CABG) remains unclear. We sought to perform a post-hoc analysis of the Surgical Treatment of Ischaemic Heart Failure (STICH) trial to investigate this association in patients treated with medical therapy (MED) with or without CABG.

Methods: From July 24, 2002, to May 5, 2007, 1212 patients with ischaemic cardiomyopathy were enrolled in the STICH trial (NCT00023595) from 99 sites in 22 countries, and were randomly assigned to undergo CABG plus MED or MED alone. We completed a post-hoc analysis of this trial. Patients with paired left ventricular end-systolic volume index (ESVI) measured at baseline and 4-months were included in our analysis. The association between change in ESVI from baseline to 4-months and cardiovascular mortality or all-cause mortality was assessed in MED arm and CABG plus MED arm.

Findings: 523 patients were included, with 291 (55.6%) assigned to MED arm and 232 (44.4%) to CABG plus MED arm. At a 4-month follow-up, ESVI reduction was more likely to occur among patients undergoing CABG plus MED. After a median follow-up of 10.3 years, for each 26% (1- standard deviation) decrement in ESVI, it was associated with a 22% lower risk of cardiovascular mortality (HR 0.78; 95% CI, 0.65-0.94) and 19% lower risk of all-cause mortality (HR 0.81; 95% CI, 0.69-0.95) in MED arm, whereas this association was not shown in CABG plus MED arm (cardiovascular mortality: HR 0.90; 95%CI, 0.74-1.10; all-cause mortality: HR 0.93; 95%CI, 0.79-1.09). A 16% reduction in ESVI was determined to be the most appropriate threshold of change in ESVI in the MED arm.

Interpretation: In patients with ischaemic cardiomyopathy, left ventricular volume change was associated with long-term prognosis after medical therapy alone, whereas was likely not an optimal benchmark for evaluating the survival benefits associated with CABG. A more than 16% reduction in ESVI might assist in therapeutic efficacy assessment and prognostic evaluation in medically treated patients.

Funding: National Natural Science Foundation of China; Natural Science Funds of Guangdong Province.