Heart Scan Ratio Flags Dangerous Lung Pressure Pattern Before Valve Replacement

Older patients with severe aortic stenosis who are scheduled for transcatheter aortic valve replacement may carry a hidden warning sign in a simple echocardiographic measurement, according to a retrospective study published in the journal Cardiovascular Ultrasound. The research, conducted at a single center, followed 667 patients treated between January 2015 and December 2022 and found that a ratio derived from routine ultrasound imaging of the heart could identify those at higher risk of a particularly harmful form of pulmonary hypertension before they ever went to the operating table.

The ratio in question is known as the right ventricular–pulmonary artery uncoupling index, expressed in this study as the tricuspid annular plane systolic excursion divided by the systolic pulmonary artery pressure, abbreviated TAPSE/PAPs. The numerator, TAPSE, is a surrogate measure of how well the right ventricle contracts along its long axis, while the denominator, PAPs, reflects the pressure load the right ventricle must work against. When the ratio falls, it signals that the right ventricle is no longer adequately adapting to elevated pulmonary pressures — a state called uncoupling. The study asked whether this noninvasive echocardiographic index, which the authors call eTAPSE/PAPs, could predict which patients had combined pre- and post-capillary pulmonary hypertension, or CoPH, as confirmed by invasive right heart catheterization.

Why focus on CoPH? Pulmonary hypertension in aortic stenosis is classified by catheterization into subtypes using the 2022 ESC/ERS guideline thresholds: mean pulmonary artery pressure above 20 mmHg defines pulmonary hypertension, and the subtypes are separated by pulmonary vascular resistance and pulmonary capillary wedge pressure. Isolated post-capillary pulmonary hypertension, or IpcPH, is defined by mean pulmonary artery pressure above 20 mmHg, pulmonary vascular resistance below 2 Wood units and wedge pressure above 15 mmHg, whereas combined pre- and post-capillary pulmonary hypertension is defined by mean pressure above 20 mmHg, resistance above 2 Wood units and wedge pressure below 15 mmHg. The combined form carries a pulmonary vascular disease component, and previous work cited by the authors has linked it to increased postprocedural mortality and hospital readmissions in patients undergoing TAVR for aortic stenosis.

The study population consisted of all consecutive patients who underwent TAVR for native severe symptomatic aortic stenosis at the center during the study period, with TAVR indications determined by a multidisciplinary Heart Team. Before the procedure, every patient received a comprehensive transthoracic echocardiographic evaluation and right heart catheterization. On the echocardiogram, systolic pulmonary artery pressure was estimated by adding the peak systolic pressure gradient between the right ventricle and right atrium, derived from the continuous-wave Doppler profile of the tricuspid regurgitation jet, to the right atrial pressure, which was assessed from the diameter and collapsibility of the inferior vena cava. Right ventricular systolic function was evaluated using TAPSE. The invasive catheterization measured mean, systolic and diastolic pulmonary artery pressures, pulmonary capillary wedge pressure, systolic right ventricular pressure, pulmonary vascular resistance and cardiac output by the Fick formula.

The investigators applied strict exclusions to sharpen the analysis. They removed patients who underwent valve-in-valve interventions, those with incomplete right heart catheterization data, those with a hypothetical follow-up shorter than three years because their procedure was performed after December 2019, those without technical success at the end of the procedure according to Valve Academic Research Consortium criteria, those without a complete pre-procedural echocardiogram, and those with pre-capillary pulmonary hypertension. The primary endpoint was all-cause mortality at two years, with follow-up defined as the time from the procedure to the last documented contact with the patient while alive or to the time of documented death.

The results centered on a clear pattern. Of the 667 patients, 299 — 44 percent — presented with pulmonary hypertension on right heart catheterization, and of these, 47 percent had isolated post-capillary disease and 53 percent had the combined form. Patients with combined pulmonary hypertension showed higher invasive mean pulmonary artery pressure and pulmonary vascular resistance than the no-PH and IpcPH groups, and both the invasive and echocardiographic TAPSE/PAPs ratios were lower in the combined group. The echocardiographic ratio showed a moderately positive correlation with pulmonary vascular resistance, with a Spearman’s Rho of 0.52 and a p value of 0.025, and was associated with combined pulmonary hypertension with an odds ratio of 1.29 and a 95 percent confidence interval of 1.10 to 1.30. The echocardiographic and invasive versions of the ratio were also moderately positively correlated with each other, with a Spearman’s Rho of 0.54 and a p value below 0.001.

Receiver operating characteristic curve analysis quantified how well the echocardiographic ratio discriminated the presence of combined pulmonary hypertension, yielding an area under the curve of 0.740. The optimal cut-off value was 0.29 mm/mmHg, with a sensitivity of 72 percent and a specificity of 60 percent. During follow-up, 157 deaths were recorded. Kaplan-Meier analysis showed a significant difference in two-year overall mortality when patients were stratified by the 0.29 cut-off, with a log-rank statistic of 4.94 and a p value of 0.026. In univariate Cox regression, the echocardiographic ratio was significantly associated with all-cause mortality, and it remained independently associated with mortality in a multivariate model that included the baseline characteristics differing significantly between the pulmonary hypertension groups.

The authors place their findings in a broader context. Pulmonary hypertension is well recognized as being associated with aortic stenosis, with reported prevalence in the literature ranging from 40 to 75 percent, and the 44 percent figure in this cohort sits within that range. Pre-procedural pulmonary hypertension is a known predictor of worse outcomes after TAVR, and prior work by the same institutional group demonstrated that increased pulmonary vascular resistance independently predicts worse long-term survival, while patients with isolated post-capillary pulmonary hypertension had outcomes comparable to those without pulmonary hypertension. The present findings are consistent with that picture, showing worse survival in patients with combined pulmonary hypertension compared with those without pulmonary hypertension or with the isolated post-capillary form, and no differences between the IpcPH and no-PH groups. Heterogeneous prognostic cut-off values for the TAPSE/PAPs ratio in TAVR populations have been reported in the literature, ranging from 0.55 to 0.39 mm/mmHg, which motivated the authors to focus specifically on predicting the combined subtype.

The clinical implication the authors draw is about triage rather than treatment. Right heart catheterization is the gold standard for diagnosing pulmonary hypertension, but it carries rare but serious risks, including pulmonary artery rupture in fewer than 0.5 percent of cases. Because the echocardiographic TAPSE/PAPs ratio is easily obtained via routine transthoracic imaging, the authors conclude that it may help identify patients with symptomatic aortic stenosis undergoing TAVR who are at higher risk of combined pulmonary hypertension and who may benefit from right heart catheterization for more accurate pre-operative risk assessment. To their knowledge, this is the first study to demonstrate a moderate but significant association between the echocardiographic ratio and combined pulmonary hypertension specifically in patients with aortic stenosis undergoing TAVR, suggesting a potentially important role for noninvasive assessment of right ventricular–pulmonary artery coupling in identifying early signs of pulmonary vascular disease progression in this population.

The study’s limitations deserve equal attention. It is a retrospective, observational, non-randomized registry study, which inherently limits causal inference and introduces potential selection bias. No follow-up echocardiographic or catheterization data were available, so serial changes in pulmonary pressures and right ventricular coupling after TAVR could not be examined. The population consisted predominantly of patients with high-gradient aortic stenosis, and although right ventricular–pulmonary artery uncoupling has been shown to be a relevant prognostic marker in other aortic stenosis subtypes, the findings may not generalize across the full spectrum of disease phenotypes. Finally, only a small proportion of patients in the cohort exhibited reduced TAPSE, likely reflecting the relatively early stage of aortic stenosis in the studied population, and the authors call for additional studies including patients with more advanced, long-standing disease to better define and refine the optimal cut-off value of the ratio. Within those boundaries, the study offers a concrete, low-cost signal: a single number from a standard heart ultrasound, checked against the 0.29 mm/mmHg threshold, may help flag which valve replacement candidates should be considered for invasive hemodynamic testing before their procedure.

Subject of Research: Use of the echocardiographic TAPSE/PAPs ratio to identify combined pulmonary hypertension in patients undergoing transcatheter aortic valve replacement

Article Title: Right ventricular-pulmonary artery uncoupling identifies higher risk of combined pulmonary hypertension in patients undergoing TAVR

Article References: Putortì, F., Fabris, T., Mesiani, C., Tripi, S., Strosio, M., Garaventa, M., Capomolla, A., Panza, A., Sasso, G., Tamanna, S., Pedagna, A., Cecchetto, A., Cardaioli, F., Masiero, G., Fovino, L. N., Fraccaro, C., Napodano, M., & Tarantini, G. (2026). Right ventricular-pulmonary artery uncoupling identifies higher risk of combined pulmonary hypertension in patients undergoing TAVR. Cardiovascular Ultrasound, 24(1), Article 17. https://doi.org/10.1186/s12947-026-00379-1

Image Credits: AI Generated

DOI: 10.1186/s12947-026-00379-1

Keywords: aortic stenosis, TAVR, pulmonary hypertension, right ventricular function, TAPSE/PAPs ratio, echocardiography, right heart catheterization, risk stratification, combined pulmonary hypertension, mortality, cardiovascular ultrasound, Right