Study of stress-strain loops on cardiotoxicity related to immune checkpoint inhibitors.

Objective: To evaluate the effect of immune checkpoint inhibitors (ICIs) on left ventricular myocardial work by pressure-strain loop (PSL).

Methods: Forty-three immunotherapy patients were enrolled in the case group, and another 43 healthy volunteers were enrolled in the control group. They were examined by echocardiography before immunotherapy (T0 phase), after three cycles of treatment (T3 phase) and after six cycles of treatment (T6 phase). Conventional echocardiographic parameters, left ventricular global longitudinal strain (GLS), and myocardial work indices, including global work index (GWI), global constructive work (GCW), global work waste (GWW), and global work efficiency (GWE), were collected for analysis to compare the results of the different immunotherapy cycles.

Results: There were no statistically significant differences of baseline characteristics, conventional echocardiographic parameters, left ventricular strain, and myocardial work indices between T0 phase and control group (all p > .05). There were no statistically significant differences in LVEF between T0, T3, and T6 phase (all p > .05). GLS, GWI, GCW, and GWE were decreased and GWW was increased in T3 and T6 phase. There were no statistically significant difference between GLS in T3 and T0 phase (q = .9057, p > .05). The difference was statistically significant between GLS in T6 and T0 phase (q = 5.5651, p < .01). The difference was statistically significant between GLS in T3 and T6phase(q = 4.6594, p < .01). There were statistically significant difference in GWI, GCW, GWE, and GWW in the T3 and T6 phase compared with the T0 phase (p < .01).

Conclusion: PSL can effectively evaluate the effect of ICIs on left ventricular myocardial work, to provide a new method for the early clinical detection of ICIs-related cardiotoxicity.