[Is the clinical course of non-rheumatic aortic regurgitation the same as that of rheumatic aortic regurgitation?].

To determine whether non-rheumatic (NR) aortic regurgitation (AR) has the same clinical and postoperative courses as rheumatic (R) AR, we performed a retrospective study using pre- and postoperative M-mode echocardiograms in 23 patients who underwent aortic valve replacement (AVR) under myocardial protection with hypothermic cardioplegia. The etiology of AR was diagnosed by two-dimensional echocardiography. The NR-AR group consisted of nine patients including four with aortic valve prolapse (AP) and five with bicuspid valve (BV), and the R-AR group included 14 patients. Patients with preoperative end-diastolic dimensions (EDD) of less than 6.0 cm were excluded from this study. The indication for AVR was NYHA functional class III or severer. The severity of preoperative NYHA functional class was similar among these three groups. During the 18-month follow-up period (range 2-32 months), there were no post-operative deaths nor congestive heart failure. Ages at surgery ranged from 17 to 54 years; 10 (71%) of 14 patients with R-AR were 40 years old or older, while seven (78%) of nine with NR-AR were under 39 years old (p less than 0.05). The pre-operative left ventricular end-diastolic pressure (LVEDP) in patients with BV-AR was highest among these three groups (R-AR: 14.5 +/- 3.9 mmHg, AP-AR: 9.5 +/- 4.1 mmHg, BV-AR: 22.0 +/- 2.7 mmHg, p less than 0.05). There was no significant difference in pre-operative M-mode echocardiographic results, except for the end-systolic dimension (ESD) between R-AR (5.20 +/- 0.55 cm) and BV-AR (4.78 +/- 0.18 cm) (p less than 0.05). The EDD one month after AVR was still abnormal (greater than or equal to 5.4 cm) in seven of the 14 patients with R-AR, and three of the four patients with AP-AR but none of the patients with BV-ARs (p less than 0.05 vs AP-AR). All patients with pre-operative ESD of less than 5.2 cm had normal EDD one month after AVR. In conclusion, the clinical course of NR-AR is different from that of R-AR. Furthermore, AP-AR regresses more differently after AVR than does BV-AR. Therefore, it is important to consider the etiology of chronic AR in determining the timing of surgery.