Author + information
- Yukari Kobayashi1,
- Yuhei Kobayashi1,
- Helen Luikart2,
- Takeshi Nishi3,
- Dong-Hyun Choi4,
- Ingela Schnittger1 and
- William Fearon2
- 1Stanford University, Stanford, California, United States
- 2Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States
- 3Stanford University School of Medicine, Stanford, California, United States
- 4Ajou University School of Medicine, Suwon, Korea, Republic of
Invasively assessed coronary microvascular resistance early after heart transplantation (HT) predicts worse long-term outcome; however, little is known about the relationship between microvascular resistance, left ventricular function and outcomes in this setting.
A total of 100 cardiac transplant recipients had fractional flow reserve (FFR) and the index of microcirculatory resistance (IMR) measured in the left anterior descending artery and echocardiographic assessment including left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) at 1 year after HT. The primary endpoint was the cumulative survival free of death or retransplantation after 1 year.
The mean FFR, IMR, LVEF, and GLS values at 1 year were 0.87±0.06, 21.3±17.3, 60.4±5.4%, and 14.2±2.4%, respectively. FFR had no significant correlation with LVEF (p=0.94) and GLS (p=0.86). Similarly, IMR had no significant correlation with LVEF (p=0.54) and GLS (p=0.90). During a mean follow-up of 6.7±4.2 years (mean 7.7 years after transplant), the primary endpoint occurred in 24 patients (24.0%). By ROC curve analysis, IMR=19.3 and GLS=13.3% were the best cutoff values for predicting death or retransplantation. The cumulative event-free survival was significantly lower in patients with higher IMR (log-rank p=0.02) and lower GLS (log-rank p<0.001). The cumulative event-free survival can be further stratified with the combination of IMR and GLS (p<0.001, Figure). By multivariate Cox-proportional hazards model, higher IMR and lower GLS were independently associated with the long-term death or retransplantation (elevated IMR, HR=2.50, p=0.04 and reduced GLS, HR=3.79, p=0.003).
Invasively assessed coronary microvascular resistance (IMR) does not correlate with left ventricular systolic function (GLS) at 1 year after heart transplantation. IMR and GLS determined at 1 year are independent predictors of late death or retransplantation.
IMAGING: FFR and Physiologic Lesion Assessment