OBJECTIVE
To compare early results of cardiac surgery for ischemic cardiomyopathy (ICMP) with stress imaging data.
MATERIAL AND METHODS
Two groups of patients with ICMP were analyzed. Group 1 (n=12) comprised of patients with a complicated early postoperative period (death, intra-aortic balloon counterpulsation, inotropic support for more than 5 days at the intensive care unit), group 2 (n=20) — uncomplicated postoperative period. We analyzed preoperative dobutamine stress echocardiography data, left ventricular ejection fraction (LV EF), LV end-systolic volume indexed to body surface area (ESVI), LV end-diastolic volume indexed to body surface area (EDVI), impaired local contractility, global longitudinal strain, LV myocardium mass. We also calculated LV contractility reserve and LV productivity indicator (power/mass ratio). Myocardial perfusion scintigraphy with 99mTc-MIBI in accordance with 2-day rest/load protocol with adenosine triphosphate (ATP) was used to assess LV perfusion and hemodynamics (EF, end-diastolic and end-systolic volumes, diastolic function). All patients underwent coronary artery bypass surgery (CABG) with LV reconstruction (34%) and mitral valve repair (40%) in some cases. Surgical risk was assessed using Euroscore II scale.
RESULTS
Euroscore II scores were comparable in both groups (5.1±1.6 vs. 5.8±1.6). There were significant between-group differences in EDVI (134.9±40.0 vs. 110.6±11.6 ml/m2, p=0.02), LV EF (28±5.0 vs. 33±4.3%, p=0.006), WMSI (2.32±0.17 vs. 2.07±0.23, p=0.003), global strain (–4.1±3.5 vs. –7.3±2.2%, p=0.004) and right ventricular function in favor of the 2nd group. However, viability and power/mass ratio were similar. No significant scintigraphy differences were noted. In the 1st group, LV EF at rest, LV EF under stress and LV peak ejection rate at rest were lower compared to the 2nd group (24.5±5.1 vs. 30±5.2%, p=0.004; 25.5±5.8 vs. 27.5±5.29%, p=0.049; 1.01±0.29 vs. 1.2±0.29 EDV/s, p=0.01, respectively). ROC-analysis of stress echocardiography data showed threshold value of ESVI 60.2 ml/m2 and LV EF over 37%.
CONCLUSION
In patients with ICMP, myocardial perfusion and LV function (power/mass ratio) are parallel and not associated with complications in early postoperative period. Preoperative stress echocardiography parameters (LV ESVI <60.2 ml/m2 and LV EF >37% or resting EF increase by more than 7.16%) are valuable to predict uncomplicated postoperative period after cardiac surgery for ICMP.
