Early regression of left ventricular hypertrophy after aortic valve replacement by the Ross procedure detected by cine MRI.

AIM

The primary objective of our study was to assess the time course of left ventricular remodeling after the Ross procedure with the use of cine magnetic resonance imaging (MRI).

METHODS

In a prospective study, 10 patients with isolated aortic valve disease were examined prior to aortic valve surgery, as well as at early follow-up (mean 4 weeks) and at late follow-up (mean 8 months) after pulmonary autograft aortic valve replacement (Ross procedure). The heart was imaged with a 1.5 T MR scanner along the short and long axes using a breath-hold, electrocardiogram (ECG)-triggered, cine gradient-echo sequence (FLASH). Myocardial mass and ventricular function were assessed.

RESULTS

After aortic valve replacement, left ventricular myocardial mass (LVM) decreased by 13% (261 +/- 74 g to 230 +/- 65 g, p < 0.05) in the early postoperative period and by a further 16% in the late postoperative period to 192 +/- 31 g (p < 0.05). In addition, left ventricular end-diastolic and end-systolic volumes decreased from preoperative 187 +/- 89 mL (LV EDV) and 73 +/- 59 mL (LV ESV) to 119 +/- 55 mL and 56 +/- 42 mL, respectively, in the early postoperative period. In the late postoperative period, there was a further decrease to 98 +/- 30 (p < 0.05) and 33 +/- 19 mL, respectively. Ejection fraction did not change markedly after surgery (preoperatively 61 +/- 13% vs. 56 +/- 14% postoperatively). Patients with leading aortic stenosis were characterized by predominant regression of LVM and patients with leading aortic regurgitation by predominant regression of LV EDV (each p < 0.05).

CONCLUSION

Cine MRI allows accurate assessment of left ventricular structure and geometry before and after aortic valve replacement with pulmonary autograft and is very sensitive in detecting relatively small changes of left ventricular myocardial mass and volumes early after hemodynamic relief as well as during serial assessment.