In a retrospective study published in Echo Research & Practice, researchers identified that a significant proportion of patients undergoing transcatheter aortic valve replacement (TAVR) for severe aortic stenosis exhibit dysfunction in multiple heart chambers, a condition often missed by conventional diagnostic criteria. The study, conducted by a team including Thomas Meredith and Mayooran Namasivayam, analyzed echocardiographic data from 234 patients to characterize strain values across the left ventricle, left atrium, and right ventricle. The findings suggest that while left ventricular function is the primary focus of current clinical assessments, subclinical impairment in other chambers is prevalent and associated with higher early mortality risk.

The research team aimed to describe the distribution of strain values in a contemporary cohort of patients with severe aortic stenosis and to determine the incidence of chamber dysfunction using established strain thresholds. By quantifying strain in the left ventricle, left atrium, and right ventricle, the investigators sought to assess whether a multi-chamber approach could enhance prognostic stratification beyond existing models that primarily rely on left ventricular ejection fraction and standard hemodynamic criteria.

The study screened an institutional database for patients who underwent TAVR between 2018 and June 2023, ensuring that pre- and post-procedural echocardiograms of suitable image quality were available. The final cohort consisted of 234 patients, with a mean age of 81 years and 60% male.

Chamber impairment was defined using consensus strain thresholds that have demonstrated prognostic power in large trials. Left ventricular impairment was defined by a global longitudinal strain (GLS) threshold of 15%, while left atrial impairment was determined by left atrial reservoir strain (LASr) values below 24% for males and 21% for females over the age of 65. Right ventricular impairment was defined by a free-wall strain value below 20%. Multi-chamber impairment (MCI) was defined as the presence of dysfunction in two or more chambers. The researchers also developed a modified cardiac damage staging system that incorporated these strain-based criteria into an established model proposed by Généreaux et al.

The results revealed that strain-defined chamber impairment was common in this population, with 29% of patients exhibiting multi-chamber impairment. Left atrial dysfunction was the most frequent isolated abnormality, accounting for 88% of single-chamber impairment cases. This finding supports the pathophysiological sequence in pressure-overload states, where increased left ventricular filling pressures impact atrial mechanics before overt ventricular dysfunction becomes apparent. Isolated right ventricular impairment was rare, occurring in only 10.3% of cases, while isolated left ventricular impairment without concurrent atrial dysfunction was identified in just 1.7% of patients.

Following TAVR, the cohort demonstrated modest improvement in chamber function, predominantly in the left ventricle. The mean change in left ventricular global longitudinal strain was +1.8 ± 3.53%, which was statistically significant in pairwise analysis. In contrast, changes in right ventricular free-wall strain (+1.24 ± 6.69%) and left atrial reservoir strain (+0.9 ± 7.61%) were not statistically significant. Patients with multi-chamber impairment showed numerical trends toward greater improvement in left ventricular strain compared to those without MCI, but these differences did not reach statistical significance, suggesting that while some recovery occurs, upstream chamber dysfunction often persists after the procedure.

At 12-month follow-up, patients with three-chamber impairment experienced a significantly increased mortality risk compared to those without any chamber impairment. The hazard ratio for 12-month mortality was 5.49, with a 95% confidence interval of 1.5 to 19.469, indicating a five-fold higher risk of death. This association persisted in multivariate analyses after adjusting for covariates such as age, sex, chronic kidney disease, STS score, atrial fibrillation, and coronary artery disease. The convergence of survival curves at approximately 24 months suggests that multi-chamber impairment is particularly predictive of early post-procedural outcomes, while longer-term survival may be influenced by additional factors including age and comorbidities.

The addition of multi-chamber strain criteria to the established damage staging system reclassified 27% of patients into higher risk categories, with 63 patients moved to worse grades and none to lower grades. However, the modified system did not significantly improve predictive accuracy over the established model at maximum follow-up. The Akaike Information Criterion (AIC) for the modified system was 581.3, compared to 578.6 for the established system, indicating no meaningful improvement in model fit. Nevertheless, patients classified as modified stage 4 demonstrated significantly worse mortality compared to those in stage 0, with a hazard ratio of 3.0, suggesting that the most advanced forms of chamber dysfunction identified by strain may still provide incremental prognostic value in selected patients.

The study highlights the limitations of relying solely on left ventricular function for risk stratification in severe aortic stenosis. The high prevalence of left atrial dysfunction, even in the absence of overt ventricular failure, underscores the importance of comprehensive multi-chamber assessment. The discordance between calculated aortic valve area and dimensionless index in patients with multi-chamber dysfunction likely reflects more substantial myocardial remodeling and contractile inefficiency, associated with reduced stroke volume index. These findings suggest that conventional severity classification paradigms may underestimate the extent of cardiac damage in this population.

Several limitations warrant consideration, including the single-centre retrospective design and the modest sample size, which limit the generalizability of the findings. The cohort consisted of patients at the end-stage of the disease spectrum, so the incremental prognostic utility of multi-chamber assessment in earlier disease stages remains unknown. Variability in the timing of post-TAVR echocardiographic assessment may have influenced the evaluation of chamber recovery, and technical challenges in obtaining left atrial and right ventricular strain may have led to an underestimation of multi-chamber impairment in patients with suboptimal image quality.

The authors conclude that larger, prospective studies with standardized timing of echocardiographic assessment and longer follow-up are needed to validate the prognostic utility of multi-chamber strain imaging in TAVR patients. The relationship between strain patterns and functional outcomes, including exercise capacity and quality of life, also warrants further exploration, as these endpoints may be more sensitive to changes in chamber function than all-cause mortality. The potential utility of artificial intelligence and machine learning approaches to integrate multiple strain parameters into a unified risk prediction model represents a promising avenue for further research, particularly given the complex interactions between chambers that may not be captured by analysis of individual chamber function.

This study provides important insights into the prevalence and prognostic implications of multi-chamber cardiac dysfunction in patients undergoing TAVR. While the addition of strain data improves damage detection, its incremental prognostic value over conventional models appears modest in this cohort. However, comprehensive strain imaging may identify patients requiring closer surveillance and targeted post-TAVR therapy, offering a potential avenue for improving outcomes in this high-risk population. The findings emphasize the need for a more nuanced approach to cardiac assessment that accounts for the interconnected nature of heart chamber function in severe aortic stenosis.

Subject of Research: Strain characterization of multi-chamber cardiac dysfunction and associated prognosis in patients undergoing TAVR for severe AS

Article Title: Strain characterization of multi-chamber cardiac dysfunction and associated prognosis in patients undergoing TAVR for severe AS

Article References: Meredith, T., Roy, D., Mohammed, F., Pomeroy, A., Feneley, M. P., Muller, D. W. M., Hayward, C., & Namasivayam, M. (2026). Strain characterization of multi-chamber cardiac dysfunction and associated prognosis in patients undergoing TAVR for severe AS. Echo Research & Practice, 13(1), Article 13. https://doi.org/10.1186/s44156-026-00122-6

Image Credits: AI Generated

DOI: 10.1186/s44156-026-00122-6

Keywords: Strain, characterization, multi-chamber, cardiac, dysfunction, associated, prognosis, patients, undergoing, TAVR, severe, scientific research