Effect of beta-blocker therapy on left ventricular responses to three different cardiotoxic regimens in cancer patients

Purpose: Analysis of ejection fraction (EF) and myocardial mechanics in cancer patients who receive potentially cardiotoxic (CTX) regimens may identify subclinical left ventricular (LV) damage. We compared cardiac function and chemotherapy regimens associated with CTX to identify whether there is a difference among regimens. We also sought whether beta-blocker (BB) therapy is cardio-protective to this population. Methods: We studied 140 patients (48±14y, 109 women) receiving anthracycline [grp A, n=52, 47±16y], trastuzumab [grp T, n=48, 52±13y] or T after A [grp AT, n=40, 45±9y]. Conventional echo indices (EF, mitral annular s' velocity) and global longitudinal peak systolic strain (GLS) were measured at baseline and follow-up (7±7 months). Patients who decreased GLS≥11% were followed another 6 months. Decisions on initiation of BB were made on clinical grounds. Results: Anthracycline doses were similar between grps A and AT (216±118 mg/m2, 213±49 p=0.89). Although ΔEF was similar among grps, reduction of s' was the greatest in grp AT (grp A, -0.6±2.5; T, -0.5±1.6; and AT, -1.7±1.9; p=0.02 between grps). Of 42 patients who decreased GLS≥-11%, 19 were treated with BB [BB(+)] and 23 without [BB(-)]. Heart rate was not different between BB(+) and BB(-) during follow-up. The patients treated with BB significantly increased EF 6 months later (from 52.6±5.6% to 57.4±6.0, p<0.001) but BB(-) did not (56.7±5.9, 56.0±5.2, p=0.17) (p<0.001 between grps). The effects of BB were similar in all regimens (Fig). Similarly, there was a significant difference between the grps (p=0.004) in s' change [BB(+) 7.7±1.7cm/s, 8.4±1.7; BB(-) 7.7±1.6, 7.3±1.6]. Figure 1 Figure 1 Conclusions: Impaired LV function is most associated with combined A+T therapy. Progression of LV dysfunction appears to be avoided in patients administered BB.