Significado diagnóstico y pronóstico del Gated-SPECT en mujeres con bloqueo de rama izquierda y baja probabilidad pre-test para cardiopatía isquémica


Our aim was to study perfusion patterns and outcome associated with left bundle branch block (LBBB) in women with low pretest probability for coronary artery disease (CAD) and its relationship with ventricular function. Material and methods: We studied 441 women for whom we collected clinical data and followed-up for about 3 years. Perfusion defects were expressed as percentage of affected myocardium. Global left ventricular ejection fraction (LVEF) and end-diastolic (EDV) and end-systolic (ESV) volumes were calculated, and regional function was measured. Results: Mean age was 72.3 ± 9.2 years; follow up was 37.5 ± 10.4 months. Thirty patients presented a normal perfusion study, and 20 had perfusion defects. According to LVEF, the patients were divided in two groups. Group 1: Stress LVEF stress <50% (36.7 ± 4.2%), n = 6 (12%). Group 2 with LVEF ≥50% (69.6 ± 11.4%), n = 44. Ventricular volumes were higher in group 1 (ESV = 106.8 ± 25.9 ml vs 25.1 ± 16 ml; p = 0.000 and EDV = 161.2 ± 30.4 ml vs 76.5 ± 23.7 ml; p = 0,000). At follow-up, no patient presented a major cardiovascular event. Conclusions: Although the presence of LBBB difficults the interpretation of Gated SPECT studies, abnormal perfusion or function is not associated with higher incidence of cardiovascular events in women with low pretest likelihood of CAD.

Key words: Women, pretest likelihood, LBBB, gated-SPECT, ischemic cardiomyopathy, cardiovascular events, false positives.