Pulmonary perfusion and NYHA classification improve after cardiac resynchronization therapy

Background: Evaluation of cardiac resynchronization therapy (CRT) often includes New York Heart Association (NYHA) classification, and echocardiography. However, these measures have limitations. Perfusion gradients from ventilation/perfusion single-photon emission computed tomography (V/P SPECT) are related to left-heart filling pressures and have been validated against invasive right-heart catheterization. The aim was to assess if changes in perfusion gradients are associated with improvements in heart failure (HF) symptoms after CRT, and if they correlate with currently used diagnostic methods in the follow-up of patients with HF after receiving CRT.

Methods and results: Nineteen patients underwent V/P SPECT, echocardiography, NYHA classification, and the quality-of-life scoring system "Minnesota living with HF" (MLWHF), before and after CRT. CRT caused improvement in perfusion gradients from V/P SPECT which were associated with improvements in NYHA classification (P = .0456), whereas improvements in end-systolic volume (LVESV) from echocardiography were not. After receiving CRT, the proportion of patients who improved was lower using LVESV (n = 7/19, 37%) than perfusion gradients (n = 13/19, 68%). Neither change in perfusion gradients nor LVESV was associated with changes in MLWHF (P = 1.0, respectively).

Conclusions: Measurement of perfusion gradients from V/P SPECT is a promising quantitative user-independent surrogate measure of left-sided filling pressure in the assessment of CRT response in patients with HF.