Left ventricular muscle mass regression after aortic valve replacement

A critical review of hemodynamic changes and left ventricular remodeling after surgical aortic valve replacement and percutaneous aortic valve replacement

The introduction of transcatheter aortic valve replacement (TAVR) in clinical practice has widened options for symptomatic patients at high surgical risk; however, it is not known whether TAVR has equivalent or prolonged benefits in terms of left ventricular (LV) remodeling.

METHODS

To explore the relative hemodynamic benefits and postoperative LV remodeling associated with TAVR and surgical aortic valve replacement (SAVR), we performed a critical review of the available literature. A total of 67 studies were included in this systematic review.

RESULTS

There is at least equivalent if not slightly superior hemodynamic performance of TAVR over SAVR, and TAVR showed lower prosthesis-patient mismatch compared with SAVR. However, LV mass appears to regress to a greater degree after SAVR compared with TAVR. Aortic regurgitation, paravalvular in particular, is more common after TAVR than SAVR, although it is rarely more than moderate in severity. Improvements in diastolic function and mitral regurgitation are reported in only a handful of studies each and could not be compared across prosthesis types.

CONCLUSIONS

The published data support the hemodynamic comparability of SAVR and TAVR, with the higher incidence of prosthesis-patient mismatch in SAVR offset by higher incidence of paravalvular leak in TAVR. These results highlight the need for further studies focusing on hemodynamic changes after valve therapy.

Systematic review of the outcome of aortic valve replacement in patients with aortic stenosis

BACKGROUND

After the establishment of aortic valve replacement procedure for aortic stenosis, there are heterogeneous studies and varying reports on outcome. An analysis that compares individual studies to summarize the overall effect is still lacking. This study systematically analyzes the change in left ventricular (LV) mass index and ejection fraction after aortic valve replacement in adult patients.

METHODS

We performed MEDLINE and bibliographic searches and included 27 articles published between 1980 and 2003 about the outcome of valve replacement in 1546 aortic stenosis patients. To allow comparisons, we stratified the patients into early (0-6 months), intermediate (7-24 months), and late (25-120 months) follow-up groups for the analysis of both LV mass regression and ejection fraction. We separately analyzed five articles that reported groups of patients with low preoperative ejection fraction.

RESULTS

Increase in ejection fraction after surgery is more pronounced in the patients that have low preoperative ejection fraction (28% +/- 4.3%(preop) vs 40% +/- 9.4%(6-41 months) follow-up). Patients with normal or high preoperative ejection fraction have variable outcomes. However, regression of LV mass is uniformly achieved regardless of age, sex, time of operation, or types of valve substitute. Furthermore, LV mass regresses predominantly within the first 6 months after surgery (g/m2, 181 +/- 25.8(preop) vs 124 +/- 27(6 months), 117 +/- 15(24 months), and 113 +/- 14(120 months) follow-up).

CONCLUSIONS

This systematic review supports the concept that aortic stenosis patients with LV dysfunction show a clear functional improvement after aortic valve replacement. Ventricles regress rapidly and reach their approximate final size within the first 6 months of surgery.

Nineteen-millimeter prosthetic aortic valves allow normalization of left ventricular mass in elderly women

BACKGROUND

Implantation of small aortic valve prostheses has been reported to be associated with impaired left ventricular (LV) mass regression and incomplete resolution of symptoms although these data have been generated largely with male patients. Therefore we sought to determine the clinical and hemodynamic outcomes of female patients who received a 19-mm aortic valve.

METHODS

Between May 1995 and December 2000, 38 female patients (average age 73 years, range 42 to 89) underwent isolated aortic valve replacement (AVR; n = 22) or AVR plus coronary artery bypass graft surgery (CABG; n = 16) with a 19-mm aortic prosthesis. The average New York Heart Association (NYHA) class was 3.08 and of the 26 patients who had angina, 47.2% were in CCS class III or IV. Clinical and echocardiographic follow-up was done an average of 33.4 months (8 to 72) after surgery.

RESULTS

Operative mortality was 10.5%. Overall survival at an average of 33 months was 71.1%. The average NYHA class was 1.52 +/- 0.34 postoperatively (p < 0.001 versus preoperative) and 95% had no anginal symptoms or were in Canadian Cardiovascular Society class I. The LV mass index showed significant regression (114 +/- 11 g/m2 to 89 +/- 9 g/m2, p = 0.001) despite an effective orifice area index (EOAI) of 0.64 +/- 0.09 cm2/m2.

CONCLUSIONS

Despite a very small EOAI, elderly female patients with 19-mm prosthetic aortic valves can experience a satisfactory improvement in symptoms and normalization of LV mass. This finding suggests that small prosthetic aortic valves continue to have an application in contemporary cardiac surgical practice. The current perception of patient-prosthesis mismatch may need to be reconsidered for select populations.