A novel ventricular systolic workload index enhances prognostic evaluation using gated single photon emission...

We aimed to create a new combined left ventricular (LV) systolic function index (left ventricular systolic workload index: LEVESWI-1 and LEVESWI-2) in a gated single-photon emission computed tomography (gSPECT) study to estimate major adverse cardiovascular events (MACE: nonfatal myocardial infarction or cardiac death).

We analyzed 2727 consecutive patients with suspected coronary artery disease who underwent gSPECT (age 63.82 ± 11, male 60.73%). LEVESWI was obtained through the relationship between LV end-systolic volume (ESV), noninvasive SBP measurement, body surface area, approximate noninvasive LV systolic pressure, and stress heart rate (stress-HR). (LEVESWI-1 = ESV-index × 8.5/stress-HR; LEVESWI-2 = SBP × 0.9/stress-HR). During a follow-up of 3.85 ± 2.7 years, MACE were evaluated. Multivariate Cox regression analysis (MCRA) and receiver operating characteristic curve analysis were used.

In MCRA age greater than 66 years (hazard ratio: 3.29, P  < 0.001); diabetes (hazard ratio: 1.86, P  = 0.008), ST-segment depression greater than or equal to 1 mm (hazard ratio : 1.95, P  = 0.005), METs less than 6.08 (hazard ratio: 1.85, P  = 0.029), LV ejection fraction less than or equal to 57% (hazard ratio: 2.4, P  = 0.005), summed stress score greater than 6 (hazard ratio: 2.32, P  = 0.002), LEVESWI-1 greater than 1.46 mmHg/ml/m²/bpm (hazard ratio: 2.18, P  = 0.017) and LEVESWI-2 greater than 1.34 mmHg/m²/bpm (hazard ratio: 1.98, P  = 0.01) were the independent predictors of MACE (Harell's C -statistic: 0.85; Akaike information criterion: 1003.64). The index LEVESWI was the principal predictor of MACE and improved the stratification of Vall-d'Hebron-Risk-Score-II for detecting MACE (net reclassification improvement: 85.5%; P  < 0.001).

LEVESWI is a new tool that incorporates key hemodynamic variables and offers a better perspective of ventricular systolic function as an independent predictor of MACE.