Introduction Mitral valve (MV) surgery is the standard treatment for MV disease. During past decades interventional treatments were implemented, raising awareness of MV treatment particularly in the elderly patient group. We analysed changes of referral patterns, baseline characteristics and outcomes of elderly patients undergoing MV surgery during the past two decades.

Methods Our in-hospital database was retrospectively explored for patients treated surgically for MV disease. Patients with concomitant and redo-procedures, as well as endocarditis were left in the study cohorts. This yielded 1788 patients treated between 1994 and 2015. Of those 471 patients (26.3%) were aged ≥75 years. This group was further divided into two cohorts according to the year of their surgery, Decade-1 (1994–2005, total n = 701, ≥75 yrs n = 113/16.1%) and Decade-2 (2006–2015, total n = 1087, ≥75 yrs n = 358/32.9%).

Results Patient age increased from 77.8 ± 3.0 yrs (Decade-1) to 79.6 ± 3.1 yrs (Decade-2, p < 0.01). Patients treated in Decade-1 were more likely to be in NYHA class IV (22.1% vs. 5.0%, p < 0.01) and to have impaired renal-function (45.1% vs. 5.6%, p < 0.01) and LV-Function (37.2% vs. 11.7%, p < 0.01) as well as peripheral vascular disease (37.2% vs. 9.2%, p < 0.01). Proportion of rheumatic MV disease decreased (26.5% [n = 30] vs. 11.7% [n = 42], while degenerative disease increased (43.4% [n = 49] vs. 56.7% [n = 203], p = 0.01). The rate of MV-repair for degenerative disease increased from Decade-1 to 2 (51.0% [n = 25] vs. 71.9% [n = 146], p < 0.01), the rate of re-operative procedures did not change (6.2% vs. 9.8%, p = 0.34). MV surgery was more often performed as a combined procedure in Decade-2 (46.9% [n = 53] vs. 62.6% [n = 224], p < 0.01). Correspondingly, ischaemic time increased from 70.4 ± 26.1 to 78.1 ± 28.4 min during the two decades (p = 0.01). Postoperative 1-, 12- and 24 months survival improved significantly from Decade-1 to 2 (87.9%, 75.7%, 72.9% vs. 92.9%, 87.1%, 83.6%, p_logrank=0.01).

Conclusions During two decades of MV surgery, the number of elderly patients increased and their survival continuously improved. While they were referred earlier for surgery, valve pathology changed towards degenerative disease, concomitant procedures increased and MV-repair was achieved more frequently.