Differences at surgery between patients with bicuspid and tricuspid aortic valves.

AIM: To determine differences in surgical procedures and clinical characteristics at the time of surgery between native bicuspid aortic valves (BAV) and tricuspid aortic valves (TAV) in patients being followed up after aortic valve surgery (AVS).

METHODS: In this retrospective cohort study in a non-academic hospital, we identified patients who had a surgeon's report of the number of native valve cusps and were still being followed up. We selected patients with BAV and TAV, and used multivariable regression analyses to identify associations between BAV-TAV and pre-specified clinical characteristics.

RESULTS: Of 439 patients, 140 had BAV (32%) and 299 TAV (68%). BAV patients were younger at the time of surgery (mean age 58.6 ± 13 years) than TAV patients (69.1 ± 12 years, p < 0.001) and were more often male (64% vs 53%; p = 0.029). Cardiovascular risk factors were less prevalent in BAV than in TAV patients at the time of surgery (hypertension (31% vs 55%), hypercholesterolaemia (29% vs 58%) and diabetes (7% vs 16%); all p < 0.005). Concomitant coronary artery bypass grafting (CABG) was performed less often in BAV than in TAV patients (14% vs 39%, p < 0.001), even when adjusted for confounders (adjusted odds ratio (adj.OR) 0.45; 95% CI: 0.25-0.83). In contrast, surgery of the proximal aorta was performed more often (31% vs 11%, respectively, p < 0.001; adj.OR 2.3; 95% CI: 1.3-4.0).

CONCLUSIONS: Whereas mechanical stress is the supposed major driver of valvulopathy towards AVS in BAV, prevalent cardiovascular risk factors are a suspected driver towards the requirement for AVS and concomitant CABG in TAV, an observation based on surgical determination of the number of valve cusps.