Implant mechanical aortic valves and start anticoagulation and save young patients (<70 years) or ‘dogs howl and the caravan will move on’

The choice of biological or mechanical surgical aortic valve prosthesis should balance valve durability with the potential adverse effects of oral anticoagulation. Current guidelines [1, 2] recommend implantation of mechanical valves in younger patients undergoing aortic valve surgery. However, the proportion of aortic valve replacements performed with mechanical devices is already low and numbers are further declining. Long-term outcomes after surgically implanted biological versus mechanical aortic valve prostheses are a matter of debate, and data seem to be conflicting. Most previously published data were based on non-randomized observational studies with propensity score matching. These studies are at risk of some inherent biases from lack of randomization including selection bias, missing follow-up and residual confounding [3]. Evidence from prospective randomized trials is scarce and demonstrates either better survival with a mechanical valve than with a bioprosthetic valve [4] or a significantly lower risk of valve failure and reoperations with mechanical valve prostheses [5].

In this issue of the Journal, Jeremy Chan et al. report data from patients 50–70 years old who underwent isolated aortic valve replacement surgery between 1996 and 2023 and investigated early and long-term outcomes. One thousand seven hundred eight patients with a median age of 63.6 years were included in this single-centre study, and 69.7% received a biological prosthesis. Inverse propensity score weighting revealed no short-term differences in outcomes between individuals who received biological or mechanical valves. Patients who received mechanical prostheses had significantly better long-term survival. Moreover, further analyses could confirm that the size of the valve prostheses matters. Patients with a small (19 mm) biological prosthesis had a worse long-term survival. Additionally, individuals with a size 21 mm mechanical prosthesis had a significantly better survival compared with size 19, 21 and 23 mm biological prosthesis. Finally, patients with severe patient–prosthesis mismatch exhibited a significantly lower survival rate compared to those with moderate or no patient–prosthesis mismatch [6].

The authors have to be congratulated for conclusively demonstrating that mechanical aortic valve replacement (m-AVR) saved patient years as compared to biological AVR (b-AVR). These results [6] corroborate all study outcomes released by our group [7–10]. Important side note: similar results were already reported in previous years [11–13].

What went wrong in the last two decades? In a historical context, we dare to ask: what led to decreasing age limits for b-AVR and the inclusion of patient choice in EACTS/ESC and JACC/AHA guidelines [1, 2]? An assertion could be that Registry Studies from the American Continent, the host of nearly all commercial valve industries, suggested that biological prosthesis fare better in the aortic position as compared to mechanical AVR irrespective of age [14, 15]. The mandatory lifelong prescription of vitamin K antagonists (derogatively termed ‘rat poison’) in m-AVR is most often utilized as ‘killer phrase and rhetorical strategy’ to coerce patients to opt for a b-AVR.

The latter publications and the global interest of the commercial TAVI industry to marginalize the m-AVR option for patients have set the stage for a ruthless exploitation of patients’ ignorance [16]. It is a cold fact in clinical medicine: (i) the implantation of an m-AVR precludes any future TAVI implantation and thence ridicules the ‘envisioned’ life time management in aortic valve diseased patients [17] and (ii) ‘the physician’s advice is the patient’s choice’ was perverted by guidelines. These ‘evidence based medicine documents’ serve specialists in the field of cardiology to advice patients according to the best medical knowledge—currently published guidelines endorse the implantation of biological scaffolds in an ever-younger aortic valve patient population. The ‘final verdict’ about the dismal outcome of b-AVR and TAVI in middle-aged patients were published recently [9, 18, 19].

In conclusion, the patient is a legal entity and trusts his disease-ridden soul to his treating cardiologists, cardiac surgeons, hospital carriers, commercial device manufactures and guideline-writing professional societies [20]. We as professional scholars/physicians/surgeons should take care that the ever-increasing literature favours the implantation of m-AVR in young and mid-aged patients. We should take care to avoid a development that guideline authors, councillors of professional societies and treating physicians will be made legally responsible for treatment suggestions for patients against the best and latest evidence. We may have passed the stage that ‘dogs are howling and the caravan will move on’. Outcome reality is biting commercial valve industry interests and their henchmen. More and more clinician scientists augur the correction of currently published guidelines. We conclude that the choice of an m-AVR versus b-AVR in young patients is an ethical decision and calls for a more paternalistic approach in advising patients in need.

DATA AVAILABILITY

No data were curated by the authors.