Viable myocardium not linked to long-term CABG benefit for ischemic cardiomyopathy
Myocardial viability was not linked to a long-term benefit from CABG in patients with ischemic cardiomyopathy, according to results from the STICH study published in The New England Journal of Medicine.
Viable myocardium was associated with left ventricular systolic function improvement regardless of treatment, although this was not related to long-term survival, according to the study.
“Patients seem to benefit whether or not they have a positive or negative result of a myocardial viability test,” Julio A. Panza, MD, FACC, chief of cardiology at Westchester Medical Center in Valhalla, New York, told Healio.
Researchers analyzed data from 601 patients (mean age, 61 years; 87% men) with CAD and an LV ejection fraction of 35% or lower. Patients were assigned CABG with medical therapy or medical therapy alone. These patients also underwent dobutamine echocardiography, single-photon emission tomography or both within 90 days before or after randomization and before therapy was initiated. Imaging was also performed to assess LV function at baseline and 4 months after randomization.
The primary outcome was all-cause death. Follow-up was conducted every 4 months during the first year of the study and every 6 months afterward, for a median of 10.4 years.
Of the patients in the study, 81% had myocardial viability.
Patients assigned CABG plus medical therapy had a lower incidence of all-cause death compared with those assigned medical therapy alone (182 deaths among 298 patients assigned CABG with medical therapy vs. 209 deaths among 303 patients assigned medical therapy alone; adjusted HR = 0.73; 95% CI, 0.6-0.9). There was no significant interaction between the presence or absence of myocardial viability and the beneficial effect of CABG with medical therapy compared with medical therapy alone (P = .34).
Patients with myocardial viability had an increase in LVEF despite their assigned treatment. No association was seen between LVEF changes and subsequent death.
“These findings do not imply that myocardial viability tests are useless, but rather that their results should be taken in conjunction with the multiplicity of factors that one needs to consider when making the decision about bypass surgery in this high-risk population of patients,” Panza said in an interview. – by Darlene Dobkowski
For more information:
Julio A. Panza, MD, FACC, can be reached at Division of Cardiology, Westchester Medical Center, 100 Woods Road, Macy Pavilion, Suite 100, Valhalla, NY 10595; email: email@example.com.
Disclosures: Panza reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.