Left ventricular mass regression after aortic valve replacement with CryoLife-O'Brien stentless aortic bioprosthesis.

BACKGROUND AND AIM OF THE STUDY: Left ventricular (LV) hypertrophy has been shown adversely to affect LV function and late outcome after aortic valve replacement (AVR). The study aim was to assess the time course of LV mass regression (LVMR) after AVR with a CryoLife-O'Brien stentless bioprosthesis, and to identify factors affecting late reduction of myocardial hypertrophy. METHODS: In total, 113 patients (60 males, 73 females; mean age 70.9+/-6.5 years) were studied by echocardiography preoperatively, at discharge, at six and 12 months postoperatively, and yearly thereafter. LV diameter and thickness were measured using M-mode echocardiography; LV mass was calculated using the Devereux formula and indexed by body surface area (BSA). RESULTS: LV end-systolic diameter, end-diastolic diameter, septal thickness and wall thickness decreased significantly after surgery (p <0.001). LV mass index (LVMI) was reduced by 16.6, 13.6, 10.1, 3.1, 3.3, 1.7, 2.6, and 1.8% at discharge and at 6 months and 1, 2, 3, 4, 5, and 6 years, respectively. Most LVMR occurred within the first year, with further (not significant) reductions at later examinations. Male sex (p = 0.002), arterial blood pressure > or =150 mmHg (p <0.001), LV ejection fraction (LVEF) < or =35% (p = 0.01), NYHA functional class > or = III (p = 0.01), atrial fibrillation (p <0.001), mean transvalvular gradient > or =40 mmHg (p = 0.001), and prevalent aortic incompetence (p <0.001) were factors influencing LVMR, independently of baseline effective orifice area and prosthesis size. CONCLUSION: AVR with the CryoLife-O'Brien stentless prosthesis resulted in significant LVMR. These findings encourage the use of this bioprosthesis in appropriate patients.

The A-Med right heart support for off-pump coronary artery bypass grafting.

BACKGROUND: Off-pump coronary artery bypass grafting (OPCAB) presents several advantages but, mainly due to the impaired diastolic filling of the right ventricle, the displacement of the heart can cause hemodynamic instability. The aim of this study was to investigate the possible role of the A-Med right heart support during OPCAB. METHODS: We report our early experience with the A-Med system (A-Med, West Sacramento, CA, USA) during OPCAB. The system consists of a coaxial cannula, a microcentrifugal pump and a control console. The coaxial cannula is passed through the right atrium with the tip of the cannula positioned in the main pulmonary artery. Thus the blood is actively removed from the right atrium and returned to the pulmonary artery. RESULTS: We successfully used this right heart support in 2 patients undergoing elective OPCAB. In both cases the system was used during the exposure of the proximal portion of the obtuse marginal branch. A mean pump flow of 3.2 l/min guaranteed normal cardiac output and hemodynamic stability during the exposure of the posterior target area. No complication occurred and the patients were discharged shortly after surgery. CONCLUSIONS: In our early experience the A-Med right heart support was safe and effective and allowed achievement of hemodynamic stability during exposure of the posterior areas of the left ventricle.

The CryoLife O'Brien stentless porcine aortic bioprosthesis: 5-year follow-up.

BACKGROUND: Mortality, morbidity, complication rates, and echo hemodynamic results using the Cryolife O'Brien stentless aortic bioprosthesis over a 5-year period are reported. METHODS: The stentless valve was implanted in 97 conscecutive patients, 54 male and 43 female, mean age 70.9 +/- 6.5 years. All patients underwent preoperative, discharge (early study), 6-month (intermediate study), and late (18.3 +/- 10.4 months) echocardiography. RESULTS: The actuarial 5-year survival rate was 93.9% +/- 3%. Aortic regurgitation was absent in 95.5%, mild in 3.4%, and moderate in 1.1%. Peak and mean systolic gradients were significantly lower at discharge (p < 0.001) and at the 6-month follow-up (p < 0.001) but did not significantly fall further at the late study (p = NS). The effective orifice area index at discharge (p < 0.001) and at 6 months (p < 0.001) differed significantly from preoperative values, but variations at late study were not significant (p = NS). Left ventricular mass index decreased early postoperatively (p < 0.001) and at 6-month assessment (p < 0.001) with a further significant reduction at late echocardiography (p = 0.04). CONCLUSIONS: The 5-year results of this stentless valve showed a low rate of valve-related complications with excellent hemodynamic performance in all valve sizes.

Open heart surgery in patients with dialysis-dependent renal insufficiency.

OBJECTIVE: Chronic renal failure (CRF) is commonly considered a significant factor for increased morbidity and mortality after cardiac surgery. METHODS: To assess the risk in our population we retrospectively analyzed 28 patients (16 men and 12 women, mean age 58.1+/-10.8 years) with end-stage renal disease (ESRD) undergoing cardiac surgery between 1989 and 2001. Sixteen (57.2%) patients had isolated coronary artery bypass grafting (CABG), nine (32.1%) had isolated valve replacement, and three (10.7%) underwent combined CABG and valve replacement. Preoperatively, 20 (71.4%) patients were on hemodialysis and eight (28.6%) on peritoneal dialysis. Mean preoperative duration of dialysis was 38.7+/-24.9 months (range, 3 to 93 months). RESULTS: There were two perioperative deaths (30-day mortality, 7.1%). Actuarial survival at 1, 2, 5, and 12 years was 0.85+/-0.7, 0.73+/-0.10, 0.65+/-0.12, and 0.54+/-0.14, respectively. Among 22 survivors, mean NYHA class was 1.7+/-0.8 (p < 0.001 vs. preoperatively) and mean CCS class was 1.6+/-0.6 (p < 0.001 vs. preoperatively). CCS/NYHA functional class IV (p = 0.01), urgent/emergency operation (p < 0.001), LVEF < 35% (p < 0.001) were strongly related to early and late mortality. CONCLUSIONS: Open-heart operations can be performed with acceptable short- and long-term results in patients with CRF on dialysis. Adequate preoperative management with identification of high-risk patients and a more aggressive approach before the onset of symptoms of cardiac failure are advisable.