Off-pump coronary artery bypass graft surgery with a pulsatile catheter pump for left ventricular dysfunction

We describe the use of a novel device, the pulsatile catheter pump, in patients with left ventricular dysfunction undergoing off-pump coronary surgery. During a 1-year period, 14 patients (mean ejection fraction 28% +/- 8%) underwent off-pump coronary surgery using the pulsatile catheter pump. We recorded neither mortality nor major adverse cardiovascular and cerebral events. Mean support time was 55 +/- 13 minutes. The average flow generated by the pulsatile catheter pump, as calculated per patient, was 2.4 +/- 0.2 L/min (range, 2.2 to 2.8 L/min). Our results show that the pulsatile catheter pump is clinically safe and provides adequate mechanical circulatory support in patients with impaired left ventricular function undergoing off-pump coronary artery surgery.     

Long-term outcome after coronary artery bypass grafting in patients with severe left ventricular dysfunction

BACKGROUND: The aim of this study was to define the potential for long-term survival with severe left ventricular dysfunction after coronary bypass and to quantify any improvement in overall functional status. METHODS: Left ventricular dysfunction was confirmed preoperatively and the long-term survival and functional outcome after bypass was determined by follow-up studies obtained during the span of a decade. RESULTS: From 1/1990 to 12/1999, 86 patients with severe left ventricular dysfunction (mean ejection fraction, 0.18 +/- 0.03; range, 0.10 to 0.20) underwent coronary artery bypass grafting. There were 10 perioperative deaths (11% mortality). The mean survival was 55 months (standard deviation +/- 34 months; range, 2 to 141 months) with an actual 5-year survival rate of 59% (actuarial 5-year 65%, 10-year 33%). Echocardiography obtained between 1 and 6 months, 6 months and 1 year, 1 and 2 years, 2 and 4 years, 4 and 6 years, and 6 and 11 years showed the ejection fraction improved to 0.29 +/- 0.08 (p < 0.001), 0.31 +/- 0.14 (p < 0.002), 0.35 +/- 0.08 (p < 0.001), 0.27 +/- 0.10 (p = 0.002), 0.36 +/- 0.14 (p = 0.004), and 0.30 +/- 0.11 (p = 0.004), respectively. At 1 to 6 months, 6 months to 1 year, and 1 to 2 years, the diastolic left ventricular dimension was unchanged, but the systolic left ventricular dimension decreased significantly from 5.02 +/- 0.77 cm to 4.26 +/- 0.91 cm (p = 0.046), 3.98 +/- 1.43 cm (p = 0.08), and 4.10 +/- 1.14 cm (p = 0.07). The preoperative New York Heart Association classification for all patients improved from 2.8 +/- 0.8 to 1.6 +/- 0.7 (p < 0.001) after a mean of 53 months (standard deviation +/- 34 months). CONCLUSIONS: Patients with severe left ventricular dysfunction can derive long-term benefit from coronary bypass through improved left ventricular contractility as documented by a significantly decreased systolic left ventricular dimension and increased ejection fraction. Successful bypass is associated with a 59% actual 5-year survival rate and significantly improved New York Heart Association functional class.     

Time-related mortality for women after coronary artery bypass graft surgery: a population-based study

OBJECTIVE: This study explores the relative early and late mortality risks in women and men after coronary artery bypass graft surgery. METHODS: This was a retrospective cohort study (n = 54,425 patients, 12,079 women) using clinical data for all patients who underwent isolated coronary artery bypass graft surgery in Ontario between fiscal years 1991 and 1999 obtained from the Cardiac Care Network database, with outcomes of early (< or =1 year) and late (>1 year up to 10 years) interval mortality identified through linkage to administrative databases. RESULTS: Female surgical candidates were older (65 vs 62 years, P <.0001) and higher-risk patients. The risk-adjusted survival of female patients was worse than that of male patients in the first year after coronary artery bypass graft surgery, but their long-term mortality was similar to that of male patients. The Cox proportional hazards model for early mortality had an adjusted female hazard ratio of 1.44 (95% confidence interval, 1.29-1.61; P =.02). This significantly differed from the late mortality model, which had a hazard ratio of 0.89 (95% confidence interval, 0.78-1.0; P =.06). CONCLUSIONS: Early mortality was significantly higher for women after coronary artery bypass graft surgery, despite adjustment for confounding factors. However, the long-term relative mortality risk for women appeared equivalent to or even better than that experienced by men as early as 1 year after coronary artery bypass graft surgery. This population-based study of long-term mortality supports the benefits of coronary artery bypass graft surgery for women in the current era. However, further research is needed to identify ways to reduce early postoperative mortality in women.     

Unrecognized left ventricular thrombus during reoperative coronary artery bypass grafting

Left ventricular thrombus after myocardial infarction is relatively common but rarely threatening enough to warrant surgical removal at the time of coronary revascularization. The rare cases of ventricular thrombectomy described in the literature involve a pedunculated thrombus. We describe an urgent coronary revascularization procedure in a patient who had unrecognized left ventricular thrombus. The large clot was detected by transesophageal echocardiography after decannulation in a hemodynamically unstable patient. The thrombus was removed after placing the patient back on cardiopulmonary bypass emergently. He recovered and was discharged with no neurologic sequelae. Aggressive removal of clot using cardiopulmonary bypass is warranted even for the critically ill patient.     

Off-pump coronary artery bypass surgery in the left ventricular dysfunction.

OBJECTIVE: The purpose of this study is to report our experience in off-pump coronary artery surgery in patients who have left ventricular dysfunction. METHODS: Off-pump coronary artery surgery was performed to 48 patients who were chosen randomly among 265 patients having two or more coronary artery disease and whose ejection fraction (EF) was less than 30%. In these patients fractioned shortening (FS) was evaluated by echocardiography, EF with multiple gated acquisition (MUGA) and ischaemic regions with myocardial perfusion scintigraphy both pre- and postoperatively. Coronary artery angiography was done to all patients at the end of the 1st year and patients were evaluated according to New York Heart Association (NYHA) classification. RESULTS: There were three deaths. The clinical situations of 41 of 45 patients (91.1%) improved after the operation. These four patients who didn't improve in NYHA status were the ones in whom complete revascularization couldn't be done. The FS and EF values were significantly increased at the 1st month, and 1st year. The constant perfusion defects and irreversible damaged areas changed into dynamic myocardial tissue in the 1st year scintigraphies. DISCUSSION: Off-pump CABG can be done with an acceptable mortality and clinic results in patients who have ventricular dysfunction.     

Early and midterm clinical outcome in patients with severe left ventricular dysfunction undergoing coronary artery surgery

BACKGROUND: Patients presenting with severe left ventricular (LV) dysfunction undergoing coronary artery surgery are at increased risk of perioperative morbidity and mortality. The present study investigated early and midterm outcomes in a consecutive series of patients with severe LV dysfunction undergoing coronary surgery at our institution. METHODS: Data on 5,195 consecutive patients undergoing coronary artery bypass grafting (CABG) alone (in-hospital mortality 1.35%) from April 1996 to August 2002 were prospectively recorded in the Patient Analysis and Tracking System. Two hundred and fifty patients (median age 65 years [interquartile range, 57 to 70]) with preoperative left ventricular ejection fraction less than 30% (74 off pump; 29.6%) were identified and early and midterm clinical outcomes analyzed. Propensity scores were used to take account of the imbalance in the distribution of prognostic factors between the on-pump and off-pump groups. RESULTS: Patients undergoing on-pump surgery were less likely to have current congestive heart failure, insulin-dependent diabetes, a history of hypertension, have had gastrointestinal tract surgery or an ulcer, or unstable angina. They had on average lower Parsonnet scores and New York Heart Association and Canadian Cardiovascular Score ratings. However they were more likely to have more extensive coronary artery heart disease and to require more grafts than those undergoing off-pump surgery. After adjustment for consultant team and propensity scores no differences between groups with regard to in-hospital mortality and morbidity were found. The only in-hospital outcome to show a significant difference after adjustment was the need for intraoperative inotropic support, which was higher in the on-pump group (odds ratio 5.1; 95% confidence interval 2.55 to 10.2; p < 0.001)). The median follow-up times for the on- and off-pump groups were 3.4 years and 1.4 years respectively. Three-year survival was higher with on-pump surgery (87% on-pump versus 73% off-pump) but this difference did not reach statistical significance after adjustment for prognostic variables (hazard ratio 0.54, 95% confidence interval 0.22 to 1.26, p = 0.16). CONCLUSIONS: In-hospital mortality and morbidity in patients presenting with severe LV dysfunction is low with comparable results with both on- and off-pump coronary artery surgery. Midterm clinical outcome is encouraging and seems to justify surgical revascularization for this high-risk group of patients.     

Silent left ventricular dysfunction during exercise after coronary artery bypass surgery

Serial changes in left ventricular function during exercise were assessed by radionuclide continuous ventricular function monitoring in 80 patients undergoing coronary artery bypass surgery before and after operation. This monitor records serial beat by beat radionuclide and electrocardiographic data and calculates the left ventricular ejection fraction every 20s. The profiles of ejection fractions during graded bicycle exercise were divided into 4 types. In type A, the ejection fraction continued to increase. In type B, the ejection fraction initially increased but decreased in late exercise. In type C, the ejection fraction did not change. In type D, the ejection fraction continued to decrease. Type A is considered to be the normal response to exercise and types B, C and, D are considered to be abnormal responses. Before operation, 8 patients showed type A, 21 type B, 13 type C, and 38 type D. After operation, 53 patients showed type A, 16 type B, 8 type C, and 3 type D. The mean ejection fraction decreased with exercise from 53%±11% to 47%±11% before surgery, but increased with exercise from 55%±10% to 64%±14% after surgery. During postoperative exercise, no patient developed chest pain but 19 patients showed a decrease in the ejection fraction in early or late exercise. A decrease in the ejection fraction is an earlier indicator of myocardial ischaemia than angina or electrocardiographic changes. Silent left ventricular dysfunction during postoperative exercise was considered to reflect myocardial ischaemia resulting from occluded grafts, ungrafted coronary arteries, or inadequate perfusion by arterial grafts. The radionuclide continuous ventricular function monitor can detect silent left ventricular dysfunction after coronary artery bypass surgery.     

The radial artery in reoperative coronary bypass surgery:

BACKGROUND: Failure of saphenous vein grafts (SVG) is a significant cause for coronary reoperation (redo CABG). The radial artery (RA) because of its availability, and versatility is well suited to use (together with internal thoracic arteries (ITA) in redo CABG, especially to replace failed SVG. We evaluated our experience where the RA was a major conduit in redo CABG over the past 5 years. METHODS: From July 1996 to June 2002, 590 consecutive patients underwent redo CABG where one or both RA(s) were used, together with LITA or RITA. The mean age was 67.3 years, 82% were male, and 19% diabetic, 419 (71%) had Class III or IV angina, 135 (23%) had left main stenosis, and 210 (36%) had an LVEF < 0.50. There were a total of 877 RA conduits (303 single, 287 bilateral), 518 new LITA or RITA. A mean of 2.8 new distal anastomoses constructed 92% (2.6 per patient)of the arterial grafts. Follow-up was at 1 month, 3 months, and then yearly. The results were compared with 6466 primary CABG performed in the same time frame, and with a prior cohort of 741 consecutive patients having redo CABG without an RA in which identical operative techniques had otherwise been used. RESULTS: The 30-day mortality was 3.9% (23 patients). Morbidity was low. Perioperative myocardial infarction occurred in 16 (2.7%) patients, stroke in 10 (1.7%), sternal infection in 10 (1.7%), donor site infection in 2 (0.3%), and IABP use in 23 patients (3.9%)-including 10 preoperatively. The results were better when compared to a prior cohort of 741 patients with redo CABG (1991 to 1996) without use of the RA. The results were inferior to that of the contemporary primary CABG. Operative mortality was 3.9% versus 0.9%, p = 0.002, myocardial infarction 2.7% versus 0.8%, p = 0.03. CONCLUSION: The use of the RA (together with ITA) in redo CABG achieved total arterial revascularization in 92% of cases and is associated with excellent results, at least equal to or superior to those achieved previously.     

Prophylactic dialysis in patients with renal dysfunction undergoing on-pump coronary artery bypass surgery

BACKGROUND: Preoperative creatinine values higher than 2.5 mg/dL are associated with markedly increased risk for both mortality and morbidity in patients undergoing coronary artery bypass surgery. We aimed to determine the effects of prophylactic perioperative hemodialysis on operative outcome in patients with nondialysis-dependent moderate renal dysfunction. METHODS: Forty-four adult patients with creatinine levels greater than 2.5 mg/dL but not requiring dialysis underwent coronary artery bypass surgery with cardiopulmonary bypass. The patients were randomly divided into two groups. In group 1 (dialysis group, 21 patients), perioperative prophylactic hemodialysis was performed in all patients. Group 2 (23 patients) was taken as a control group and hemodialysis was performed only if postoperative acute renal failure was diagnosed. RESULTS: The hospital mortality was 4.8% (1 patient) in the dialysis group, and 30.4% (7 patients) in the control group (p = 0.048). Postoperative acute renal failure requiring hemodialysis was seen in 1 patient (4.8%) in the dialysis group and in 8 patients (34.8%) in the control group (p = 0.023). Thirty-three postoperative complications were observed in the control group for an early morbidity of 52.2% (12 patients) and 13 complications occurred in 8 patients in the dialysis group (38.1%). The average length of the intensive care unit and postoperative hospital stay were shorter in the dialysis group than in the control group (p = 0.005 and p = 0.023, respectively). CONCLUSIONS: Preoperative creatinine levels higher than 2.5 mg/dL, increase the risk of mortality and the development of acute renal failure and prolong the length of hospital stay after on-pump coronary artery bypass surgery. Perioperative prophylactic hemodialysis decreases both operative mortality and morbidity in these high-risk patients.