Clinical characteristics of patients undergoing surgical ventricular reconstruction by choice and by randomization

Abstract

Objectives: The aim of this study was to confirm the generalizability of the conclusions of the STICH (Surgical Treatment for Ischemic Heart Failure) trial.

Background: Surgical ventricular reconstruction (SVR) added to coronary artery bypass grafting (CABG) did not decrease death or cardiac hospitalization in STICH patients randomized to CABG with (n = 501) or without (n = 499) SVR.

Methods: Baseline clinical characteristics of 1,000 STICH SVR hypothesis patients and 1,036 STICH-eligible Society of Thoracic Surgeons (STS) National Cardiac Database patients undergoing CABG plus SVR were entered into a multivariate model equation to predict a mortality that placed these 2,036 patients in 1 of 32 risk at randomization (RAR) groups. The number of patients in each RAR group profiled the risk of STICH treatment arms and of STICH and STS STICH-eligible patients.

Results: That 85% of the 1,000 STICH patients known to have no significant differences in baseline characteristics between the 2 treatment arms shared the same RAR group suggests that the RAR methodology has sufficient accuracy to compare RAR profiles of STICH and STS patients. RAR group was shared by 1,522 of 2,036 STICH and STS STICH-eligible patients (75%) who underwent CABG plus SVR. Differences in baseline characteristics responsible for more low-risk STICH patients and more high-risk STS patients were modest. Cox proportional hazard ratios of 1,000 STICH patients in 3 RAR groups suggested by STICH and STS RAR differences showed no differential treatment effect on survival across the low-, intermediate-, and high-risk groups.

Conclusions: The STICH conclusion of no benefit from adding SVR to CABG applies to a broad spectrum of CABG-eligible patients with ischemic cardiomyopathy. (Comparison of Surgical and Medical Treatment for Congestive Heart Failure and Coronary Artery Disease; NCT00023595).

Copyright (c) 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1. RAR Distribution of STICH SVR Hypothesis Patients Compared to Distribution of Values of Major Baseline Predictors of Risk for Each Interval

Histogram of individual STICH SVR hypothesis patients by RAR groups shows decreasing numbers of patients with increasing risk from RAR groups 1-32. The mean age, EF, and Duke coronary disease index is depicted for each RAR group. The percent of patients with a baseline history of specific cardiac and non-cardiac disorders at baseline is depicted for each RAR group.

Figure 2. RAR Profile of STICH SVR Hypothesis Patients Compared by Randomized Treatment Assignment

Patients matched by randomized treatment assignment are plotted above (CABG) and below (CABG+SVR) 0. Patients randomized to CABG not matched by a CABG+SVR patient are plotted above in blue. Patients randomized to CABG+SVR not matched by patients randomized to CABG are plotted below in red.

Figure 3. RAR Profile of 1000 STICH SVR Hypothesis Patients Compared to 1036 STS STICH-eligible CABG+SVR Patients

The 761 STICH and 761 STS CABG+SVR patients that share the same RAR number are plotted from 0 (green). Excess STICH patients not matched by STS patients are plotted above in blue. Excess STS patients not matched by STICH SVR hypothesis patients are plotted below in red.