Background and aim of the study: Pure annular dilation (PAD) is a recognized etiology of mitral regurgitation, yet few data exist to define the prognostic profile of this disorder relative to other etiologies, such as ischemia or myxomatous prolapse.
Methods: A total of 535 patients undergoing mitral repair at two institutions between 1993 and 2002 was retrospectively reviewed. PAD was defined as requiring only ring annuloplasty +/- cleft repair, without evidence of prolapse, regional wall motion abnormality, or infarction.
Results: PAD was identified in 74 patients, while alternative etiologies were myxomatous prolapse (n = 290), ischemia (n = 141), and 'other' (n = 30). PAD patients were more often female (78%) than male (38%) (p < 0.001), more often hypertensive (37% versus 26%; p = 0.003), and had a left ventricular ejection fraction (LVEF) that was lower (0.41 +/- 0.12) than those in patients with prolapse (0.51 +/- 0.11; p < 0.01) but similar to values in ischemic patients (0.38 +/- 0.10). The valve size was smaller for PAD versus prolapse (ring size 24-26 mm in 71% versus 12%; p < 0.001). The unadjusted PAD prognosis was intermediate, with five-year survival being 70 +/- 8%, compared to 87 +/- 3% for prolapse and 56 +/- 5% for ischemia (p < 0.01). Survival adjusted for differences in baseline characteristics was not different among the three groups (p > 0.10).
Conclusion: PAD is a clinically distinct etiology of mitral regurgitation associated with female gender, small valve size, a lower LVEF, and hypertension. Early, more aggressive hypertension control might improve or minimize the consequences of this predominantly female cardiac disorder.