Predictors for ventricular arrhythmia
In the present study we identified 4 factors that were associated with increased risk of VTA, including BUN>25mg/dl, EF<20%, prior NSVT, and female gender. Reduced EF and prior NSVT reflect substrate and vulnerability to sustained VTA in patients with CRT-D,19,20 while elevated BUN is correlated with diuretic use, and may therefore be a marker of more advanced HF rather than an indicator of renal dysfunction, as creatinine and eGFR did not enter the final prediction model.
Several previous publications have suggested that women may respond better to CRT with subsequent lower mortality than men.21,22 Our study suggests that among patients without LBBB, the effect of sex may be different, and that non-LBBB women may experience increased VTA risk with CRT-D. These data are consistent with our prior findings from the long-term follow-up of MADIT-CRT, in which we have shown that the pronounced benefit of CRT for the endpoint of all-cause mortality among women was restricted to those with LBBB, whereas CRT-D was associated with a trend to a mortality risk increase among women without LBBB.