Changing pattern of valve surgery

Area of Science:

• Cardiovascular Surgery
• Thoracic Surgery
• Medical Technology

Background:

• Surgical techniques and myocardial protection have improved aortic and mitral valve surgery outcomes.
• Valve repair advancements reduce the need for valve replacement.
• Patients requiring valve replacement often present with advanced disease and calcification, increasing surgical risk.

Purpose of the Study:

• To compare outcomes of aortic (AVR) and mitral (MVR) valve replacement between two distinct time periods.
• To identify predictors of postoperative low-output syndrome (LOS) and operative mortality (OM).
• To assess the impact of evolving patient risk profiles on surgical outcomes.

Main Methods:

• Retrospective review of 2898 patients undergoing AVR or MVR at Toronto Hospital.
• Comparison of an early surgical group (1982-1986) with a late surgical group (1989-1993).
• Univariable and multivariable analyses to determine predictors of LOS and OM.

Main Results:

• The late AVR group (n=997) had more high-risk patients but a lower incidence of LOS (10% vs. 14%, P=.012) and similar operative mortality (3.4% vs. 3.7%, P=.732) compared to the early group (n=782).
• The late MVR group (n=493) also had more high-risk patients, with no significant differences in LOS (19% vs. 21%, P=.361) or OM (5.8% vs. 6.9%, P=.432) compared to the early group (n=626).
• Multivariable analyses confirmed increased preoperative risk factors in the late groups for both AVR and MVR.

Conclusions:

• Despite an increasing proportion of high-risk patients undergoing AVR and MVR, operative mortality and morbidity did not significantly increase.
• Surgical advancements and perioperative care appear to mitigate risks in complex valve replacement cases.
• Outcomes for aortic and mitral valve replacement remain stable despite evolving patient complexity.