Short-term results of repeat valve replacement: a predictive factor analysis

The new-generation bioprostheses are associated with a longer lifespan, and therefore tend to be implanted in younger patients. However, with the increase in life expectancy, the trend is towards a higher rate of repeat valve replacement. Hence, the study aim was to evaluate the present mortality and risk factors for repeat valvular surgery.

A total of 183 consecutive patients (87 males, 96 females; mean age 62 years; range: 28-88 years) who underwent repeat valve replacement at the authors' institution between 2001 and 2004 was reviewed. Reoperations in these patients were required due to structural degeneration of the bioprosthesis (50%), to paravalvular leak (20%), and to prosthetic endocarditis (14%), valve thrombosis (9%), and plasty failure (9%). In total, 105 patients (57%) had received at least one bioprosthesis during the previous operation, 58 (31%) had a mechanical valve, 15 (8%) had an isolated mitral plasty, and five (2%) hybrid procedures. All preoperative and operative risk factors were studied.

The overall operative mortality rate was 6.6% (n = 12), but only 3.9% (n = 4) for the bioprosthesis reoperation. The risk factors for mortality included pulmonary hypertension (> 60 mmHg; p = 0.03), renal insufficiency (p = 0.02), more than one repeat valve replacement (p = 0.004), previous mechanical prosthesis (p = 0.02), previous mitral surgery (p = 0.019), and associated tricuspid surgery (p = 0.03).

The data acquired tended to show that repeat valve replacement of bioprostheses may be carried out with an acceptable operative risk, in connection with the majority of operations on bioprostheses being secondary to structural degeneration of the implant. Hence, in most cases a well-controlled, programmed operation would lead to very low mortality (< 4%), despite a significant morbidity rate.