Synergistic prognostication of left ventricular hypertrophy and three‐dimensional mechanical dyssynchrony in heart failure

Abstract

Aims In this study, we investigated the prognostic interplay of left ventricular hypertrophy and mechanical dyssynchrony (LVMD), both of which can be measured three‐dimensionally by gated myocardial perfusion imaging (MPI), in patients with chronic systolic heart failure (HF). Methods and results In 829 consecutive HF patients with reduced left ventricular ejection fraction less than 50%, LVMD was evaluated as a standard deviation (phase SD) of regional onset of mechanical contraction phase angles. A phase histogram was created by Fourier phase analysis applied to regional time‐activity curves obtained by gated MPI. Left ventricular mass index (LVMI) was measured by Corridor 4DM version 6.0. Patients were followed up with a primary endpoint of lethal cardiac events (CE) for a mean interval of 34 months. CE were documented in 223 (27%) of the HF patients. The CE group had a greater phase SD and a greater LVMI than those in the non‐CE group. Patients in the CE group had a more advanced age, greater New York Heart Association (NYHA) functional class, left ventricular cavity size, and left atrial diameter or septal E/e' and lower kidney or cardiac function than did patients in the non‐CE group. Phase SD > 37 and LVMI > 122.7 g/m2 were identified as optimal cut‐off values by receiver operating characteristic analyses for discrimination of the most increased risk HF subgroup from others (P < 0.0001). When classified into four patient subgroups using both cut‐off values, HF patients with phase SD > 37 (LVMD) and LVMI > 122.7g/m2 had the highest CE rate among the subgroups (P < 0.0001). Univariate analysis and subsequent multivariate analysis with a Cox proportional hazards model showed that phase SD and LVMI were significant independent predictors of CE with hazard ratios of 1.038 (confidence interval [CI], 1.024–1.051, P < 0.0001) and 1.005 (CI, 1.001–1.008, P = 0.0073), respectively, as well as conventional clinical parameters such as age, NYHA class, estimated glomerular filtration rate (eGFR), and BNP concentration. Patients with increased phase SD and LVMI had incrementally improved prognostic values of clinical parameters including age, NYHA functional class, eGFR, and BNP with increases in the global χ2 value: 5.9 for age; 139.5 for age and NYHA; 157.9 for age, NYHA, and eGFR; 163.9 for age, NYHA, eGFR, and BNP; 183.4 for age, NYHA, eGFR, BNP, and phase SD; and 192.5 for age, NYHA, eGFR, BNP, phase SD, and LVMI. Conclusions Three‐dimensionally assessed LVMD has independent prognostic values and can improve the risk stratification of chronic HF patients synergistically in combination with conventional clinical parameters.

Impaired Cardiac Sympathetic Innervation Increases the Risk of Cardiac Events in Heart Failure Patients with Left Ventricular Hypertrophy and Mechanical Dyssynchrony

“…LVMD and left ventricular mass index (LVMI) as an index of LVH were evaluated using three-dimensional data derived from resting myocardial perfusion imaging (MPI) with 99m Tc-tetrofosmin of 300 MBq, as shown by our previous study ( Figure 1 ) [ 11 , 12 , 13 ]. Briefly, MPI SPECT was performed using an ECG-gated approach with a frame rate of 16 and a single-head gamma camera equipped with a high-resolution, parallel-hole collimator.…”

“…Briefly, MPI SPECT was performed using an ECG-gated approach with a frame rate of 16 and a single-head gamma camera equipped with a high-resolution, parallel-hole collimator. LVMD and LVMI were measured using three-dimensionally reconstructed ECG-gated data of serial 10- to 14-short-axis SPECT images with the Heart Function View software (HFV version 1.1;Nihon MediPhysics, Tokyo, Japan) [ 12 , 13 ] and Corridor 4DM version 6.0 software (INVIA Medical Imaging Solutions, Ann Arbor, MI, USA) [ 11 ], respectively. LVMD was quantified as a standard deviation (SD) of phase angles (degrees) on a phase histogram ( Figure 1 ).…”

“…Besides technical issues of device implantation, this is probably because of the limited assessment using an electrical and/or two-dimensional echo data, resulting in an ineffective CRT rate of nearly 30% [ 9 , 10 ]. On the other hand, three-dimensional evaluation of LVMD and LVH can be done routinely in cardiac nuclear imaging, and our previous studies have shown the improvement of prognostic assessment using three-dimensional nuclear techniques, contributing to optimization of the selection of CRT candidates [ 11 , 12 , 13 ].…”

Three-dimensional left ventricular mechanical dyssynchrony assessed by myocardial perfusion gated-SPECT: Is there a role in cardiac resynchronization therapy?

“…13 In the study by Doi et al, left ventricular mechanical dyssynchrony was assessed as standard deviation on a phase histogram calculated by Fourier phase analysis applied to three-dimensionally obtained regional time-activity curves. 11 Three-dimensional left ventricular mechanical dyssynchrony assessed by gated-SPECT was previously shown to be a reliable and reproducible variable, 14,15 and to improve the prognostic stratification of heart failure patients when used in combination with clinical variables 14 and cardiac sympathetic nerve activity assessment. 15 The results of the study by Doi et al 11 extend while confirming previous findings suggesting that three-dimensional left ventricular mechanical dyssynchrony assessed by gated-SPECT may be an independent predictor of lethal cardiac events in heart failure patients.…”

“…15 The results of the study by Doi et al 11 extend while confirming previous findings suggesting that three-dimensional left ventricular mechanical dyssynchrony assessed by gated-SPECT may be an independent predictor of lethal cardiac events in heart failure patients. 14,15 The specific contribution of the study is that three-dimensional left ventricular mechanical dyssynchrony may further discriminate heart failure patients with mid-range to severe grades of QRS prolongation and systolic dysfunction, thus improving the prognostic assessment of such patients. Accordingly, in a previous study left ventricular mechanical dyssynchrony by phase analysis of gated-SPECT was shown to be an independent predictor of all-cause mortality in patients with non-ischemic cardiomyopathy, ejection fraction 35%-50%, and QRS duration\150 ms. 16 Furthermore, the results of the study by Doi et al 11 reflect the possibility that QRS duration may not be a parameter directly related to the presence of left ventricular dyssynchrony and therefore to the response to Cardiac Resynchronization Therapy, especially in the absence of left bundle branch block.…”