Objective To evaluate the effectiveness and diagnostic value of CorVue system alarm in identifying cardiac function changes and heart failure events of patients.
Methods Patients with chronic heart failure with transthoracic impedance monitoring function CRT-D were enrolled in our hospital from January 2015 to May 2018. Baseline data such as age, gender, heart failure etiology, NYHA heart function class, blood biochemical indicators and therapeutic drugs were collected. At 1, 3, 6 and 12 months after surgery, routine follow-up was performed in the pacemaker clinic, and unexpected follow-up was performed in the heart failure clinic or emergency department when device alarm or cardiac function deterioration occurred. The baseline data and follow-up data of the patients were analyzed retrospectively. The effective alarm and invalid alarm were defined according to whether there was a heart failure event within 30 days of the device alarm. The predicted value of the CorVue system alarm for heart failure events was calculated, and the NT-proBNP level after the alarm was observed.
Results Total 51 patients with heart failure were included in the study, with an average age of(63±8) years and women with 35.29%. A total of 73 CorVue system alarms and 23 heart failure events occurred during the 12-month follow-up. Sensitivity of CorVue alarms was 35%, specificity was 30%, positive predictive value of 11% and negative predictive value of 65%. 71% of the alarms were accompanied by an increase in NT-ProBNP level[1 623(1 160,1 902)]. After the alarm, the level of NT-ProBNP increased 32%[1 734(1 276,1 844),
P=0.001]. The NT-ProBNP levels of the effective alarm group and the invalid alarm group increased by 109%(
P=0.012) and 22%(
P=0.029) respectively[1 623(1 049,1 902)].
Conclusion The value of CorVue alarm lies in reflecting the potential changes of cardiac function, rather than simply predicting heart failure events.
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