Effects of passive cardiac containment on left ventricular structure and function: verification by volume and flow measurements.

BACKGROUND: The cardiac support device (CSD, Acorn) is a compliant, textile-mesh graft placed around the ventricles to prevent further dilatation and to improve function in congestive heart failure. The aim of this study was to verify post-operative changes in left ventricular volumes, ejection fraction, blood flow, and myocardial mass. METHODS: Fourteen patients underwent contrast-enhanced, electrocardiography-triggered electron-beam computerized tomography before and 6 to 9 months after CSD implantation. We measured volume and flow using the slice-summation method and the indicator-dilution technique. RESULTS: We found significant changes for the following parameters: end-diastolic volume decreased from 382.9 +/- 140.2 ml to 311.3 +/- 138.7 ml, end-systolic volume from 310.4 +/- 132.4 ml to 237.4 +/- 133.8 ml, end-diastolic diameter from 75.3 +/- 7.8 mm to 70.7 +/- 11.6 mm, end-systolic diameter from 65.8 +/- 7.8 mm to 60.0 +/- 14.0 mm, and myocardial mass from 298.6 +/- 79.6 g to 263.1 +/- 76.8 g. Ejection fraction increased from 20.3% +/- 6.4% to 27.8% +/- 13.1%. We found no significant differences for stroke volume (from 72.5 +/- 24.6 ml to 73.8 +/- 23.6 ml), heart rate (from 80.5 +/- 11.0 beats per minute to 76.5 +/- 6.8 beats per minute), and total cardiac output (from 5.8 +/- 1.9 liter/min to 5.6 +/- 1.8 liter/min). Mitral regurgitation fraction decreased from 30.5% +/- 15.5% to 15.6% +/- 12.8%, increasing antegrade cardiac output from 3.8 +/- 0.9 liter/min to 4.7+/-1.5 liter/min. For most parameters, pre- and post-operative values in these patients differed significantly from those in an age- and gender-matched control group. In each patient, we observed a small hyperdense stripe along the pericardium after surgery, but we observed no local complications. CONCLUSION: Three-dimensional structural and functional data obtained by computerized tomography volume and flow measurements confirm the safety and efficacy of CSD implantation.