Aortic stenosis patients with CKD at greater risk of death

The presence of chronic kidney disease (CKD) in patients with moderate to severe aortic stenosis (AS) appears to increase mortality and admissions for cardiac failure, reports a Singapore study. It may also result in fewer aortic valve replacements.

“Importantly, we demonstrated that the trends present in patients with severe AS also applied to patients with moderate to severe AS who are in the earlier course of disease,” the researchers said.

A total of 727 consecutive patients with index echocardiographic diagnosis of moderate to severe AS (aortic valve area <1.5 cm²) were included in the analysis and divided into two groups: those with CKD (estimated glomerular filtration rate <60 mL/min) and those without.

The researchers compared the baseline clinical and echocardiographic parameters among participants and created a multivariate Cox regression model. They also used Kaplan–Meier curves to compare outcomes.

Of the AS patients, 270 (37.1 percent) had concomitant CKD. The CKD group was older (78.0 vs 72.1 years; p<0.001) and had a higher prevalence of hypertension, diabetes mellitus, hyperlipidaemia, and ischaemic heart disease. [Singapore Med J 2024;65:624-630]

AS severity was similar between groups, but the CKD group had higher left ventricular (LV) mass index (119.4 vs 112.3 g/m²; p=0.027) and Doppler mitral inflow E to annular tissue Doppler e’ ratio (21.5 vs 17.8; p=0.001).

In addition, patients with CKD showed higher mortality (log-rank 51.5; p<0.001) and had more frequent admissions for cardiac failure (log-rank 25.9; p<0.001), with a lower incidence of aortic valve replacement (log-rank 7.12; p=0.008).

Multivariate analyses, adjusted for age, aortic valve area, LV ejection fraction (LVEF), and clinical morbidities, revealed the sustained independent association of CKD with increased mortality (hazard ratio, 1.96, 95 percent confidence interval, 1.50–2.57; p<0.001).

Multifactorial reasons

“The reasons for the increased adverse outcomes would likely have been multifactorial,” the researchers said. “Firstly, the coexistence of CKD could accelerate the progression of AS and lead to more rapid clinical deterioration as a result of accelerated atherosclerosis and valve calcification.” [AsiaIntervention 2019;5:32-40; Eur Heart J 2004;25:199-205; Am J Cardiol 2016;117:1972-1977] 

Previous studies have also consistently shown CKD to be independently predictive of death in patients with severe AS. [Circulation 2005;111:3290-3295; N Engl J Med 2000;343:611-617]

CKD could have direct effects on myocardial function. In the present study, patients with concomitant CKD in AS had a “distinct echocardiographic profile that is different from those without CKD,” according to the researchers.

“Although the severity of AS as measured by the aortic valve area and transaortic pressure gradients was similar, these patients demonstrated evidence of increased LV mass and slightly lower LVEF,” they said. 

In AS patients with CKD, factors such as increased AS severity, CKD itself, or the underlying cause for CKD (eg, uncontrolled hypertension or diabetes mellitus) might have caused the pathological LV remodelling.

“Indeed, all of these factors may have contributed to the development of diastolic dysfunction in this context and may also have precipitated the development of symptoms, which contributed to the adverse clinical outcomes,” the researchers said. [Korean J Intern Med 2013;28:35-44; Hypertension 2008;52:107-114]

“Further studies are warranted to better prognosticate and guide therapy in this subgroup of patients,” they noted.