March 1, 2000
View Full PaperA 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
Structured PICO
Does ventricular plication by suturing improve left ventricular dimensions and contractility in a rat model of myocardial infarction?
P
Population
Rats with myocardial infarction induced by occluding the left coronary artery 4 weeks before enrollment (n=22)
I
Intervention
Ventricular plication using a pursestring suture placed within the border zones of the infarcted area and tightened
C
Comparator
Pursestring suture placed within the border zones of the infarcted area but not tightened
O
Outcome
Left ventricular diameters (end-diastolic length, end-systolic length) and fractional shortening measured by echocardiography at 1 hour and 6 to 7 weeks after plicationsurrogate
Ventricular plication by suturing infarcted tissue acutely decreases left ventricular diameters and improves function, attenuating late ventricular remodeling in a rat model of myocardial infarction.
Abstract
BACKGROUND: The Batista procedure (cardio-reduction) 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 cardio-reduction 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.