Cardiac Functions in Long-Term Survivors of Mechanical Circulatory Support

Over the last 5 years, 12 patients (7 males and 5 females, aged 22–73 years; mean age, 54) in our institutions received ventricular assist devices (VADs) while in post-car diotomy shock. Eight patients underwent surgery for valve replacements, three for coronary artery bypass graftings and one for ventricular septal rupture (VSR) closure. The duration of VAD support ranged from 6 h to 9 days (mean, 4.2 days). Ten patients were weaned from the VADs and six survived. The six survivors were followed-up for 4–42 months (mean, 25 months); five were in New York Heart Association (NYHA) class I and one in class II. The cardiac functions in five patients who lived for more than 1 year were assessed by ultrasonic echocardiography (UCG). Pre- and postoperative UCG revealed that the ejection fraction (EF) increased from 41.7 ± 6.4% to 57.5 ± 11.3 (P < 0.01), the mean velocity of circumferential fiber shortening (mVcf) increased from 0.76 ± 0.26c/s to 0.92 ± 0.35 (P < 0.01), the left ventricular diastolic dimension (LVDd) decreased from 63.0 ± 16.4mm to 52.4 ± 10.3 (P < 0.05), and the left ventricular systolic dimension (LVDs) decreased from 48.8 ± 16.6mm to 36.8 ± 9.6 (P < 0.05). However, the patients did not show further changes in these parameters during exercise. Eight patients who had double valve replacements were observed for comparison (control group). In the control group, exercise improved cardiac output, from 4.63 ± 0.791/min to 8.05 ± 1.34 (P < 0.01), and mVcf, from 1.02 ± 0.19c/s to 1.72 ± 0.41 (P < 0.01). We concluded from these findings that VAD patients, as compared to the control patients, exhibited improvement in postoperative cardiac functions, but had lower tolerance in exercise tests.