Tohoku J. Exp. Med., 2020 June, 251(2)

Cardiac Resynchronization Therapy for Improving Non-Uniform Thickening of Left Ventricular Wall: Assessment by Quantitative Gated Myocardial Perfusion SPECT

YUJI WAKAYAMA,¹ MAKOTO NAKANO,¹ KOJI FUKUDA,¹ KOJI KUMAGAI,¹ YOSHINAO SUGAI,¹ MASANORI HIROSE,¹ NOBUHIRO YAMAGUCHI,¹ MASATERU KONDO,¹ TOMOHIRO KANETA,² HIROSHI FUKUDA,³ YUTAKA KAGAYA⁴ and HIROAKI SHIMOKAWA¹

¹Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
²Diagnostic Radiology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
³Department of Nuclear Medicine and Radiology, Tohoku University Institute of Development Aging and Cancer, Sendai, Miyagi, Japan
⁴Office of Medical Education, Tohoku University School of Medicine, Sendai, Miyagi, Japan

Cardiac resynchronization therapy (CRT) improves cardiac dyssynchrony in heart failure patients with a wide QRS electrocardiogram (ECG). Assessment of left ventricular (LV) dyssynchrony using echocardiography or other imaging modalities is important to predict CRT effectiveness. In this study, we retrospectively evaluated cardiac nuclear imaging of ECG-gated myocardial perfusion single-photon emission computed tomography (SPECT) with ^99mTc-sestamibi for CRT candidate (n = 120) with severe heart failure and wide QRS (> 120 msec) in ECG. To analyze LV non-uniformity, we used the quantitative gated SPECT (QGS) software to calculate changes in regional LV wall thickness during a cardiac cycle (i.e., wall thickening scores). Cardiac events (heart failure, ventricular arrhythmias and cardiac death) after CRT during 38 ± 22 (SD) months were also evaluated. In 97 of 120 patients who underwent QGS before and 6 months after CRT, CRT homogenized non-uniform wall thickening between septal and lateral of the LV especially in CRT responders. This observation was indicated as increase in the lateral deflection (X_WT) of wall thickening scores before CRT and its decrease after CRT. In 120 patients with QGS before CRT, the larger X_WT before CRT (ge; 16.5) predicted better prognoses after CRT. This finding was similarly observed even in patients with narrower baseline QRS (le; 140 msec; n = 41 of 120), who usually have less benefits from CRT. In conclusion, CRT improved non-uniformity of wall thickening between the LV septal and lateral regions evaluated using QGS, which is predictive of better prognosis in the chronic phase after CRT.

Keywords —— cardiac resynchronization therapy; dyssynchrony; heart failure; nuclear imaging; quantitative SPECT

© 2020 Tohoku University Medical Press.

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Tohoku J. Exp. Med., 2020, 251, 69-79

Correspondence: Yuji Wakayama, M.D., Ph.D., Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.

e-mail: yujiwaka@gmail.com