Surgical ventricular restoration based on evaluation of myocardial viability with delayed-enhanced magnetic resonance imaging.

OBJECTIVE: We examined whether the determination of myocardial viability by preoperative delayed-enhanced magnetic resonance imaging (DE-MRI) would be useful for planning surgical ventricular restoration (SVR). METHODS: Eight consecutive patients with poor cardiac function (ejection fraction < 30%) due to ischemic cardiomyopathy underwent surgical treatment based on findings of preoperative cine-MRI and DE-MRI. Our surgical strategy consisted of (1) complete revascularization on viable segments; (2) SVR in a patient with extensive nonviable segments; and (3) mitral valve plasty in a patient with a more than moderate degree of mitral regurgitation. Based on the MRI assessments, four of the patients (group A) underwent isolated coronary bypass surgery, and the other four (group B) underwent SVR and mitral valve plasty concomitantly with coronary bypass surgery. Perioperative changes in ventricular function were quantitatively assessed in each group. RESULTS: The mean end-diastolic volume index was reduced from 115 +/- 29 ml/m2 to 95 +/- 14ml/m2 in group A and from 163 +/- 35ml/m2 to 125 +/- 28ml/m2 in group B. The mean end-systolic volume index was reduced from 91 +/- 25ml/m2 to 68 +/- 16ml/m2 in group A and from 135 +/- 36ml/m2 to 98 +/- 28 ml/m2 in group B. The mean ejection fraction increased from 20% +/- 6% to 28% +/- 9% in group A and from 17% +/- 6% to 22% +/- 5% in group B. The mean New York Heart Association (NYHA) functional class was reduced from 3.0 +/- 0.8 to 1.8 +/- 0.6 in group A and from 3.5 +/- 0.5 to 2.2 +/- 0.2 in group B. CONCLUSION: DE-MRI was highly effective in helping to select which patients and which areas of the left ventricle are indicated for SVR, which contributed to excellent early clinical outcomes.

Renal outcome in off-pump coronary artery bypass grafting: predictors for renal impairment with multivariate analysis.

OBJECTIVE: : Recent studies on the efficacy of off-pump coronary artery bypass grafting (OPCABG) have reported encouraging results on postoperative renal function, but improvements can still be made. METHODS: : A total of 368 patients, none needing chronic dialysis, underwent isolated OPCABG at our institution between January 1999 and March 2005. They were divided into 3 groups according to renal function as indicated by the serum creatinine levels: group N (n = 332) with normal function, group M (n = 30) with mild to moderate renal dysfunction, and group S (n = 6), with severe renal dysfunction. Creatinine ratio and early outcomes were compared among the groups. Predictors for renal impairment were determined by multiple regression analysis. RESULTS: : In-hospital mortality rate was similar (group N, 0.6%; group M, 0%; group S, 0%). The percentage of patients with a creatinine ratio greater than 1.6 was significantly larger in group S (group N, 13%; group M, 13%; group S, 50%; P < 0.05). Postoperative hemodialysis, which was temporary, was required more frequently in group S (group N, 0.3%; group M, 3%; group S, 67%; P < 0.05). In group N, 38 patients (11%) had new renal impairment after OPCABG. Preoperative serum creatinine levels ≥2.5 mg/dL, ejection fraction <0.4, amount of blood transfusion, and more than 4 bypasses were potent predictors for postoperative renal impairment. CONCLUSIONS: : Clinical results of OPCABG on renal function were satisfactory regardless of preoperative renal function. However, perioperative renal function should be closely monitored in patients with known risk factors, even when OPCABG is performed.

Pulmonary artery augmentation using autologous vena cava in right heart bypass operations.

We obtained good results in the right heart bypass operation concomitant with the pulmonary arterial augmentation using the vena cava in 7 patients. We report the techniques used in 2 representative patients. The techniques used were a hemi-Fontan procedure with large superior vena caval patches and a bidirectional cavopulmonary shunt with superior vena caval interposition. These techniques have advantages in that the augmented pulmonary arteries have growth potential and low thrombogenicity because the procedures can be performed without the use of prosthetic materials or xenografts, especially in cases in which it is impossible to use the autologous pericardium.