It is well established that the incidence of severe aortic stenosis increases with age. Transcatheter aortic valve implantation (TAVI) has become a safe and effective alternative for elderly patients at low, intermediate, and high surgical risk. But what happens specifically in nonagenarians? This subgroup remains underrepresented and poses the greatest challenge for decision-making within a multidisciplinary team: polypharmacy, advanced chronic comorbidities, increased risk factors, and poorer outcomes. While discrepancies have been identified in short- and mid-term outcomes, what happens in the long term? Does frailty or mortality change?

This study, conducted by the Department of Cardiovascular Surgery at Mayo Clinic (Rochester, Minnesota, USA), analyzes comorbidity, frailty, nutritional status, and quality of life, evaluating the impact of variables such as mortality, stroke, and repeated hospitalizations in nonagenarian patients undergoing TAVI.

A retrospective review was conducted on the medical records of 187 consecutive nonagenarian patients who underwent TAVI between November 2009 and September 2020. All available frailty variables were included, such as:

• 5-meter walk test (frail if > 6 seconds)
• Kansas City Cardiomyopathy Questionnaire (KCCQ-12) score (frail if < 25 points)
• Katz Index of Independence in Activities of Daily Living (frail if < 5 points)
• Serum albumin levels (frail if < 3.5 g/dL)

Additionally, technical procedural variables, demographic and clinical characteristics, and biometric data were collected from electronic medical records. The vital status of the patients was obtained from the Minnesota Department of Health.

The primary study endpoint was mortality, while secondary endpoints included stroke, repeated hospitalizations, and combined events such as mortality/stroke or mortality/stroke/repeated hospitalization.

A univariate and multivariate Cox regression model was applied to analyze the relationship between the selected variables and mortality. The results were reported as hazard ratio (HR) with 95% confidence intervals (CI).

Additionally, a model incorporating “biological age” was developed, based on 20 dichotomous variables related to patient health status (comorbidities, cardiovascular risk factors, previous cardiac surgeries, functional class according to the NYHA scale, among others). A linear regression model was used to predict biological age.

Survival curves were compared with an age- and sex-matched U.S. population. Finally, a sensitivity analysis was performed to detect potential biases, confirming that no significant differences were found when comparing the obtained data.

The study analyzed a sample of 187 nonagenarian patients, with a mean age of 92 years, of whom 50% were women. Among this cohort, 73% were classified as high-risk. Regarding key demographic and clinical characteristics, 93% of patients had hypertension, 54% had peripheral vascular disease, and 75% had coronary artery disease. Severe mitral stenosis was present in 25% of cases, and only 11% required an urgent TAVI procedure.

In terms of frailty and functional variables, the 5-meter walk test was performed in 87% of the patients, with 72% classified as frail. Hypoalbuminemia was reported in 8% of cases, while a Katz Index score below 4 points was identified in 12% of the sample. The KCCQ-12 questionnaire was recorded in 133 patients (71%), with 13% reporting very poor or poor health status (KCCQ-12 score 0-24, indicative of frailty), and 30% classified within the poor to fair category (KCCQ-12 score 25-49).

Regarding procedural characteristics, 86% of the cohort received a balloon-expandable valve (Sapien®, Edwards LifeSciences®). The arterial access was transfemoral percutaneous in 57% of cases. The TAVI procedure was successful in 99% of cases, with a mean postoperative transvalvular aortic gradient of 4 mmHg (range 3-6 mmHg). Severe paravalvular leakage was observed in only 1% of patients and was resolved intraoperatively. Technical success, as defined by the Valve Academic Research Consortium-3 criteria, was achieved in 90% of cases.

Concerning periprocedural complications and survival outcomes, 26% of patients required permanent pacemaker implantation, 13% were readmitted early, and 30-day mortality was 2%. During a mean follow-up of 3.4 years, 80% of the patients died. The multivariate analysis showed that mortality was not significantly associated with any of the analyzed variables. The 1-year and 5-year survival rates were comparable to those of age- and sex-matched controls in the U.S. population. Additionally, no significant predictors were identified for the combined outcomes of mortality, stroke, or repeated hospitalization. Notably, neither chronological age nor biological age were significantly associated with the combined outcomes of mortality, stroke, or repeated hospitalization.

COMMENTARY:

Any scientific publication that gathers data on nonagenarian patients requires a considerable effort, given that the heterogeneity of aging poses a challenge to conducting studies in this population. This retrospective descriptive study provides data from a substantial sample of genuinely nonagenarian patients, with an extended follow-up period that is particularly notable for this age group. It represents an essential first step toward identifying potential areas for improvement, possibly through a preprocedural assessment conducted in collaboration with Geriatrics. However, some unanswered questions remain. Would it have been useful to have more baseline information, such as the Barthel Index, the Lawton Index, the Short Physical Performance Battery, cognitive status, gait instability, or history of previous falls, as the authors themselves acknowledge in their discussion of the study’s limitations? Could a comprehensive geriatric assessment (CGA) before the procedure have helped identify pre-frail and frail patients, allowing for targeted interventions to optimize their condition prior to undergoing TAVI? Although the study cohort likely underwent a rigorous selection process, a high proportion of patients were still classified as frail. Selecting the most robust candidates and optimizing the pre-frail and frail ones—since frailty is a potentially reversible geriatric syndrome—could influence secondary outcome variables.

What were the post-TAVI functional outcomes? Given the extended follow-up period for nonagenarians (up to 8.5 years in some patients), it is unfortunate that there is no available data on their autonomy in performing activities of daily living. The questionnaires used in the study do not fully capture these aspects. A follow-up assessment of gait speed, handgrip strength, or additional parameters within a new CGA could have provided more predictive power in evaluating the quality of life of these patients. Ultimately, from the patient’s perspective, these parameters are often the most relevant. Once a study includes a population that surpasses the country’s life expectancy, the number of additional years lived is less clinically meaningful if autonomy and independence are not considered.

Another important limitation is the underrepresentation of nutritional status in the study, as hypoalbuminemia—present in only 8% of the sample—was considered the sole nutritional marker. A more comprehensive nutritional assessment within the CGA framework would have been beneficial. It is highly likely that all these patients could have gained advantages from a pre- and post-procedural nutritional intervention, combined with multicomponent exercise programs within prehabilitation initiatives. This aspect is closely related to skeletal muscle function, overall mobility, and fall risk, which are key determinants of whether patients cross the threshold into dependency, institutionalization, and mortality—major concerns in geriatric care.

A particularly valuable aspect of this study is its distinction between chronological age and biological age. Once again, the need to evaluate patients based on functionality rather than age alone is brought into focus. Chronologically, these patients are nonagenarians, but biologically, they vary significantly. The key takeaway is that mortality was not significantly modified, meaning that these patients, who have far exceeded the average life expectancy in their region, require a multidisciplinary approach that avoids both therapeutic nihilism and iatrogenic harm—neither of which seem to have occurred in this study, apart from the high pacemaker implantation rate. Therefore, TAVI in nonagenarians is not a futile procedure, and continuous optimization of care for this growing patient population remains a priority.

REFERENCE:

Juarez-Casso FM, Singh M, Lewis BR, Sandhu GS, Arghami A, Rowse PG, et al. Long-term Stroke and Mortality Risk in Nonagenarians After Transcatheter Aortic Valve Insertion. Ann Thorac Surg. 2024 Nov;118(5):1035-1042. doi: 10.1016/j.athoracsur.2024.04.030.