M.D./MSc Student Institut universitaire de cardiologie et de pneumologie de Québec (IUCPQ).Université Laval (IUCPQ-ULaval) Québec, Quebec, Canada
Background: Patients with low-flow, low-gradient aortic stenosis (LF-LG AS) represent a high-risk population with poor outcomes following aortic valve replacement (AVR). While right ventricle-pulmonary artery (RV-PA) coupling has emerged as an important prognostic marker in heart failure, its role in risk stratification of LF-LG AS patients remains to be established. The objective of this study was to determine the prognostic value of RV-PA coupling, assessed by the tricuspid annular plane systolic excursion to pulmonary artery systolic pressure ratio (TAPSE/PASP), in patients with LF-LG AS managed conservatively or with AVR.
METHODS AND RESULTS:
Methods: Clinical and echocardiographic data were prospectively collected from 152 patients enrolled in the TOPAS (Truly or Pseudo-severe Aortic Stenosis- #NCT01835028) study. The optimal prognostic threshold value of TAPSE/PASP was determined using receiver operating characteristic (ROC) analysis. The association between TAPSE/PASP and mortality was assessed using Cox regression analysis.
Results: The mean age of the study population was 76±9 years, with 62% men (n=101). 123 (81.5%) were hypertensive, 59 (39.1%) diabetic, and 101 (66.9%) had dyslipidemia. During a median follow-up of 2.1 (0.8-4.5) years, 23 (15%) patients died. The optimal prognostic threshold of TAPSE/PASP was ≤0.60 mm/mmHg (interquartile range: 0.35-0.65 mm/mm Hg). In univariate Cox regression analyses, TAPSE/PASP was associated with increased risk of mortality (HR [95% CI] = 5.77 [1.34-24.70], p=0.01). Multivariable Cox analysis adjusted for age, sex, AVR as a time-dependent variable, and STS score confirmed that TAPSE/PASP ≤0.60 was independently associated with increased all-cause mortality (HR [95%CI]: 5.74 [1.24– 26.62], p=0.02).
Conclusion: RV-PA coupling, a marker of the efficiency with which RV stroke work is transferred into the PA, assessed by TAPSE/PASP ratio, is independently associated with increased risk of all-cause mortality in patients with LF-LG AS. The TAPSE/PASP ratio may be useful to enhance risk stratification and clinical decision-making in this challenging population.
