A new study led by the University of Bristol suggests that patients aged between 50 to 70 years experience better long-term survival rates with mechanical heart valve replacement. This is compared to those receiving biological valves. The findings are published in European Journal of Cardio-Thoracic Surgery. They challenge the current trend of favoring biological valves for this age group.
Over the last two decades, the use of biological heart valves has increased. These valves are made from animal tissue. They are especially popular among older patients. Although short-term clinical outcomes for both valve types are similar, long-term survival rates remain a point of contention.
Existing medical guidelines recommend mechanical valves for patients under 50 and biological valves for those over 65 or 70. Yet, the guidelines allow a case-by-case decision for patients aged 50 to 70. The choice between the two valves is made individually for each patient.
CLINICAL OUTCOMES FOR PATIENTS
The Bristol Heart Institute (BHI) team analyzed clinical outcomes over a 27-year period from 1996 to 2023. They focused on patients aged 50 to 70 undergoing elective and urgent heart valve replacements. The researchers examined early outcomes, long-term survival rates, repeat valve interventions, and patient prosthesis mismatch (PPM) in their study.
A total of 1,708 patients (61% male, average age 63 years) were included, with 1,191 patients (69.7%) receiving biological valve replacements.
NO SHORT-TERM DIFFERENCES, BUT LONG-TERM SURVIVAL FAVORS MECHANICAL VALVES
The study found no significant short-term differences in outcomes between patients who received biological or mechanical valves. However, when looking at long-term survival rates—up to 13 years after surgery—patients who received mechanical valves experienced significantly better survival.
Patients with a 19mm biological valve (commonly used in females) showed the poorest long-term survival rates. Conversely, those who received a 21mm mechanical valve had better survival outcomes compared to patients with either 19mm or 21mm biological valves. The study also identified severe PPM as a significant risk factor for poor long-term survival.
RECONSIDERING CURRENT TRENDS IN VALVE SELECTION
Gianni Angelini, BHF Professor of Cardiac Surgery at Bristol Medical School and Director of the Bristol Heart Institute, emphasized the implications of the study’s findings for surgical decision-making. “Our study impacts decision-making in surgical heart valve replacements. This is crucial for patients aged between 50 and 70 years old,” said Angelini. “The evidence supporting better long-term survival in patients receiving a mechanical heart valve is substantial. It suggests the current trend favoring biological valves in this age bracket should be urgently reconsidered. The survival benefit is especially clear in smaller-sized valves.”
Evaluating the Long-Term Benefits of Mechanical Valves
Biological valves do not need long-term blood thinners. However, the study suggests that mechanical valves may offer more significant long-term survival benefits. This is particularly true for patients with smaller valve sizes. The research team calls for further evaluation of the long-term advantages of mechanical valves, especially for patients aged 50 to 70.
This groundbreaking research challenges long-held assumptions about the superiority of biological valves for certain age groups. The study suggests that mechanical valves may offer better long-term survival. This is especially true for patients with smaller valve sizes. The study calls for a reevaluation of current guidelines. As the medical field continues to evolve, this research highlights the need for more personalized and evidence-based decision-making in heart valve replacement surgeries.
