Abstract
Aim
1. To evaluate the impact of preoperative left ventricular (LV) diastolic performance on early and late outcomes in patients with ischemic cardiomyopathy undergoing coronary artery bypass grafting (CABG) and surgical ventricular reconstruction (SVR).
2. To investigate LV diastolic function dynamics according to the results of tissue Doppler imaging (TDI) in these patients.
3. To assess the echographic predictors for persistence of the restrictive LV diastolic filling pattern (LVDFP) late after CABG and SVR.
Material and method
Prospective study on 157 pts with LV systolic dysfunction (LVEF <30%) who underwent CABG and SVR, evaluated including TDI preoperatively, early (<1 month), medium (3 and 12 months) and late postoperatively (mean 4,8 years). Statistical analysis used SYSTAT and SPSS. The primary outcome was the time to death from any cause or hospitalization for cardiac causes.
Results
1. The preoperative restrictive LVDFP was an independent and predominant predictor for increasing the early and late postoperative risk of cardiovascular events (p=0.001). At 5 years postoperatively, cardiovascular event-free survival was significantly higher in pts with nonrestrictive LVDFP (75%) compared with restrictive LVDFP (55,74%) (p<0.0001).
2. Conventional transmitral diastolic Doppler indices before and after CABG +SVR remained unchanged. TDI showed significant improvement before and in 3 and 12months postoperatively of both LV systolic (S: 6.1±0.9, 7.5±1.1 and 7.3±1.2 cm/sec, p<0.01) and diastolic function (e': 7.2±1.8, 8.3±1.4 and 8.8±1.5 cm/sec; E/e' ratio: 17.8±2.1, 13.1±1.7 and 11.3±1.8; Vp 3.2±0.55, 2.4±0.28 and 1.9±0.26, p<0.01).
3. The evolution of LVEF, LV end-diastolic volume (LVEDV) and mitral regurgitation (MR) severity was different in nonrestrictive group (early and late postoperatively these variables improved) compared with restrictive group (late after surgery the variables deteriorated: LVEF from 27±8% to 22±6%, LVEDV from 181±49 to 234±63 cm3 and MR degree from 0.9±0.6 to 1.8±0.7; p<0.005).
4. Regression analysis identified as predictors for persistence of a restrictive LVDFP late after surgery: E/E' ratio >14 (RR=19.3), LA dimension index >30 mm/m2 (RR=9.2), LVEDV >200 cm3 (RR=9.6), severe PHT (RR=11.4), 2 degree MR (RR=14.8).
Conclusions
1. TDI evaluation demonstrate significant improvement of LV systolic diastolic function in CABG + SVR pts, regardless of transmitral flow pattern. TDI is more sensitive and preload independent method of LV function evaluation.
2. The preoperative LVDFP has an independent and incremental prognostic value in CABG+SVR pts, strongly related to higher mortality with aggravation of LV systolic function, MR severity or LV remodeling. This might be attributable to deterioration of diastolic function induced by SVR.
3. Late after CABG+SVR the restrictive LVDFP persistence was predicted by: E/E' ratio >14, LA dimension index >30 mm/m2, LVEDV >200 cm3, severe PHT and 2 degree MR.
Effects of surgical ventricular reconstruction on diastolic function at midterm follow-up