A New Model of Ventricular Plication: A Suturing Technique to Decrease Left Ventricular Dimensions,Improve Contractility,and Attenuate Ventricular Remodeling After Myocardial Infarction in the Rat Heart

Abstract

Background: The Batista procedure (cardioreduction) is a surgical technique in patients with dilated cardiomyopathy that results in improvement of ventricular function. The purpose of this study was to test a new suturing technique without resection for cardioreduction of myocardial infarct scars in rats.

Methods and Results: Myocardial infarction (MI) was induced by occluding the left coronary artery 4 weeks before enrollment. Animals then were randomized to a control (n = 11) or treatment group (n = 11). A pursestring suture was placed within the border zones of the infarcted area and was either tightened (treated) or not (controls). Echocardiography was used to measure left ventricular diameters before, 1 hour, and 6 to 7 weeks after plication. Acutely after plication, end-diastolic length (EDL) decreased from 0.70 ± 0.03 cm to 0.53 ± 0.02 cm, P < .001; end-systolic length (ESL) decreased from 0.51 ± 0.03 cm to 0.23 ± 0.02 cm, P < .001; and fractional shortening (FS) increased from 27.6 ± 1.5% to 57.6 ± 2.3%, P < .001, whereas controls were unchanged. In control rats EDL increased from baseline at 0.73 ± 0.02 cm to 0.82 ± 0.04 cm at 6 weeks postsurgery, P < .05; ESL increased from 0.54 ± 0.02 cm to 0.66 ± 0.04 cm, P < .005; and FS decreased from 26.9 ± 1.1% to 19.2 ± 1.2% at 6 weeks, P < .05. In contrast, at 6 weeks in plicated animals, EDL was significantly less than controls at 0.64 ± 0.02 cm, P < .005; ESL was significantly less than controls at 0.39 ± 0.03 cm, P < .005, and FS was significantly better than controls at 40.5 ± 2.2%, P < .005.

Conclusion: The progressive LV enlargement between 4 and 10 weeks after MI reflects late ventricular remodeling. Plication by suturing infarcted tissue acutely decreases diameters and improves function. At 6 weeks, function remains improved over untreated animals.