Systolic anterior motion of the mitral valve: a 30-year perspective.

Objective: Systolic anterior motion (SAM) can occur after mitral valve repair (MVr), most frequently in patients with degenerative valve disease. Our initial observations (1981-1990) revealed that most patients with SAM can be successfully treated medically. Here the authors review the last 16 years of their experience with SAM after MVr.

Methods: Between January 1996 and October 2011, 1918 patients with degenerative mitral valve disease underwent MVr at our institution. We performed a retrospective analysis of SAM in this patient population.

Results: The incidence of SAM was 4.6% (89 of 1918) overall, 4.0% (77 of 1906) in patients who did not have SAM preoperatively (de novo). Compared with our previously published report, the incidence of SAM decreased from 6.4% to 4.0% (P = .03). Hospital mortality was 2.0% (38 of 1918) overall, 1.3% (14 of 1078) for isolated MVr. One patient with de novo SAM (1 of 77; 1.3%) died after emergency MVr. All patients with de novo SAM were successfully managed conservatively with intravenous fluids, α agonists, and/or β blockers. A higher incidence of SAM was associated with a left ventricular ejection fraction greater than 60% (P = .01), posterior leaflet resection (P = .048), and hypertrophic obstructive cardiomyopathy (P < .01). The incidence of SAM was lower in patients who underwent device mitral annuloplasty with a semirigid posterior band compared with a complete ring (P = .03).

Conclusions: In the more recent era, SAM occurs one-third less frequently after repair of degenerative mitral valve disease. Use of an incomplete annuloplasty band rather than a complete ring is associated with a lower incidence of SAM. The mainstay treatment of SAM continues to be medical management.