Yves Leclerc

Effect of internal mammary artery dissection on sternal vascularization

Internal mammary artery (IMA) dissection may cause sternal devascularization and ischemia resulting in sternal wound complication. To evaluate the effect of median sternotomy and IMA dissection on sternal vascular supply, sternal bone tomography was performed 7 days and 1 month after cardiac operation in 67 patients. Seventeen nondiabetic patients had single IMA grafts, 18 had double IMA grafts, and 12 had only saphenous vein grafts or valve replacement. Twenty diabetic patients were studied after any one of these operations. Seven patients were restudied 1 month after the operation. Sternal technetium-99m-methylene diphosphate tomography was performed. The sternum was visualized and focal zones of hypoactivity represented sternal hypoperfusion. The ratio of hypoactivity area over total sternal area was calculated for every patient. After median sternotomy without single or double IMA grafts, the averaged hypoperfusion ratio was 4% +/- 1% compared with 13% +/- 3% after single IMA grafts and 24% +/- 6% after double IMA grafts (p less than 0.0001). Diabetic patients without IMA, with single IMA, and with double IMAs showed hypoperfusion areas of 5% +/- 3%, 15% +/- 5%, and 23% +/- 9%, respectively, a result similar to that of nondiabetic patients. One month after operation the hypoperfusion area decreased to 2% +/- 2% (p less than 0.05) in restudied patients. Our results indicate that IMA dissection causes a significant although partial and temporary sternal ischemia, which is more severe after double IMA than single IMA mobilization and which may be incriminated in the development of sternal wound infection. This vascularization defect was not greater among patients with diabetes mellitus.

Simultaneous Determination of Aortic Valve Area by the Gorlin Formula and by Transesophageal Echocardiography Under Different Transvalvular Flow Conditions: Evidence That Anatomic Aortic Valve Area Does Not Change With Variations in Flow in Aortic Stenosis☆

OBJECTIVES The purpose of this study was to determine the impact of changes in flow on aortic valve area (AVA) as measured by the Gorlin formula and transesophageal echocardiographic (TEE) planimetry. BACKGROUND The meaning of flow-related changes in AVA calculations using the Gorlin formula in patients with aortic stenosis remains controversial. It has been suggested that flow dependence of the calculated area could be due to a true widening of the orifice as flow increases or to a disproportionate flow dependence of the formula itself. Alternatively, anatomic AVA can be measured by direct planimetry of the valve orifice with TEE. METHODS Simultaneous measurement of the planimetered and Gorlin valve area was performed intraoperatively under different hemodynamic conditions in 11 patients. Left ventricular and ascending aortic pressures were measured simultaneously after transventricular and aortic punctures. Changes in flow were induced by dobutamine infusion. Using multiplane TEE, AVA was planimetered at the level of the leaflet tips in the short-axis view. RESULTS Overall, cardiac output, stroke volume and transvalvular volume flow rate ranged from 2.5 to 7.3 liters/min, from 43 to 86 ml and from 102 to 306 ml/min, respectively. During dobutamine infusion, cardiac-output increased by 42% and mean aortic valve gradient by 54%. When minimal flow was compared with maximal flow, the Gorlin area varied from (mean +/- SD) 0.44 +/- 0.12 to 0.60 +/- 0.14 cm2 (p < 0.005). The mean change in Gorlin area under different flow rates was 36 +/- 32%. Despite these changes, there was no significant change in the planimetered area when minimal flow was compared with maximal flow. The mean difference in planimetered area under different flow rates was 0.002 +/- 0.01 cm2 (p = 0.86). CONCLUSIONS By simultaneous determination of Gorlin formula and TEE planimetry valve areas, we showed that acute changes in transvalvular volume flow substantially altered valve area calculated by the Gorlin formula but did not result in significant alterations of the anatomic valve area in aortic stenosis. These results suggest that the flow-related variation in the Gorlin AVA is due to a disproportionate flow dependence of the formula itself and not a true change in valve area.

The carpentier-edwards pericardial bioprosthesis: Clinical experience with 600 patients

Carpentier-Edwards pericardial bioprostheses were implanted in 600 patients: 416 aortic valve replacement, 115 mitral valve replacement, 6 isolated tricuspid, and 63 multiple valve replacements. The survival rates were 70% at 10 years after aortic valve replacement, 62% 8 years after mitral valve replacement, and 57% at 8 years with multiple valve replacement. Overall, 69 patients suffered one or more valve-related complications. The 10-year freedom rates from embolism were 91% (aortic valve replacement), 92% (mitral valve replacement), and 89% (multiple valve replacement), and those from endocarditis were 95%, 93%, and 85%, respectively. In 18 of the 35 patients, reoperation was due to primary valve dysfunction. Freedom from primary dysfunction was 87% at 10 years with aortic valve replacement, and at 8 years, it was 79% with mitral valve replacement and 77% with multiple valve replacement. A direct correlation was found between freedom from valve dysfunction and age of the patient at operation, with a 10-year-free rate of 90% among patients older than 59 years. This bioprosthesis has an excellent durability up to 10 years in the aortic position. More data regarding its long-term durability in the mitral position are needed. It is currently our valve substitute of choice when a bioprosthesis is indicated.

Intermittent antegrade warm versus cold blood cardioplegia: A prospective, randomized study☆

A prospective, randomized study was performed in 200 patients undergoing coronary artery bypass grafting to compare the myocardial protection obtained with intermittent antegrade warm versus cold blood cardioplegia. Preoperative and surgical characteristics of the two cohorts were similar. Intermittent antegrade infusion of warm blood cardioplegia failed to achieve sustained electromechanical arrest of the heart in 13%. The only difference in clinical outcomes was the more frequent spontaneous return to sinus rhythm after the unclamping of the aorta in the warm group (88% versus 70%, p = 0.002). Mortality (1% each) and myocardial infarction (2% and 4%) rates were similar. Rates of increase in serum activity of the isoenzyme of creatine kinase (CK-MB), CK-MB mass concentration, and cardiac troponin-T level as well as total release of troponin T were significantly lower in the warm group, and fewer patients in this group had a clinically significant increase in serum CK-MB mass (20% versus 39%, p = 0.005) and troponin T (20% versus 56%, p = 0.00001). Thus, intermittent antegrade warm blood cardioplegia is appropriate and clinically safe; the lower release of biochemical markers of myocardial damage suggests improved protection during first-time coronary artery bypass grafting.

Clinical and operative characteristics of patients randomized to coronary artery bypass surgery in the bypass angioplasty revascularization investigation (BARI)

The surgical cohort of the Bypass Angioplasty Revascularization Investigation (BARI) is the largest group of patients with multivessel coronary artery disease randomly assigned to surgical treatment. This report presents baseline and operative characteristics of the cohort and describes some aspects of the variability in surgical practice among the 14 primary clinical centers and 4 co-investigational sites participating in BARI. Preoperative clinical and angiographic data and intraoperative variables were reviewed in 892 patients who were randomly assigned to coronary artery bypass grafting (CABG) and underwent operation. Associations between patient/lesion variables and operative characteristics are described. Of patients assigned to CABG, 87% underwent an operation within 2 weeks of randomization, as recommended in the protocol. Mean age of the 892 patients was 61 years, and mean age of the 235 women was greater than that of men (64 years vs 60 years); 64% of the surgical patients were classified as having unstable angina during the 6 weeks prior to randomization. Coronary angiography demonstrated 3-vessel disease (50% diameter narrowing by caliper measurement) in 41% of patients, and disease of the left anterior descending coronary artery was present in 87% of patients. A mean of 3.1 coronary arteries per patient were bypassed, and 82% of patients received 1 (70%) or 2 (12%) internal thoracic artery grafts. Prevalence of internal thoracic grafts was lower in elderly patients (74% of patients > or = 70 years), in women (72% vs 85% in men; p < 0.01), and in black participants (65%).(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic dissection complicating coronary angioplasty in cystic medial necrosis

2. Halle AA III, Wilson RF, Massin EK, et al. Coronary angioplasty in cardiac transplant patients: results of a multicenter study. Circulation 1992;86:458-62. 3. Sandhu JS, Uretsky BF, Reddy PS, et al. Potential limitations of percutaneous transluminal coronary angioplasty in heart transplant recipients. Am J Cardiol 1992;69:1234-127. 4. Strikwerda S, Umans V, Van der Linden MM, Van Suylen RJ, BalkAH, de Feyter P J, Serruys PW. Percutaneous directional atherectomy for discrete coronary lesions in cardiac transplant patients. Am Heart J 1992;123:1686-90. 5. Gao S-Z, Schroeder JS, Hunt S, Stinson EB. Retransplantation for severe accelerated coronary artery disease in heart transplant recipients. Am J Cardiol 1988;62:876-81. 6. Copeland JG, Butman SM, Sethi G. Successful coronary artery bypass grafting for high risk left main coronary atherosclerosis after cardiac transplantation. Ann Thorac Surg 1990;49:106-10. 7. Serruys PW, de Jaegere P, Kiemeneii F, et al. A comparison ofballoonexpandable-stent implantation with balloon angiopIasty in patients with coronary artery disease. N Engl J Med 1994;331:489-95. 8. Fischman DL, Leon MB, Balm DS, et al. A randomized comparison of coronary-stent placement and balloon angioplasty in the treatment of coronary artery disease. N Engl J Med 1994;331:496-501.

Balloon mitral commissurotomy for mitral restenosis after surgical commissurotomy

Balloon mitral commissurotomy (BMC) was performed in 113 patients. Of these patients, 27 (24%) (25 women and 2 men, aged 49 +/- 13 years) had recurrent mitral stenosis 13 +/- 6 years (range 5 to 29) after surgical commissurotomy. Eleven patients (41%) were considered at high risk for surgery. BMC resulted in an increase in mitral valve area from 1.1 +/- 0.3 to 1.9 +/- 0.7 cm2 (p < 0.0001), and a decrease in mean mitral gradient from 16 +/- 7 to 6 +/- 3 mm Hg (p < 0.0001). An optimal result of BMC (increase in valve area > or = 25% with a post-BMC valve area > or = 1.5 cm2) was obtained in 18 patients (67%). The results did not differ from those observed in the 86 patients of our entire series without prior surgical commissurotomy. Patients with an optimal result of BMC had a more recent surgical commissurotomy and lesser morphologic alterations of the mitral valve than did those with a nonoptimal result. Patients with echocardiographic scores < 10 had an 80% success rate of BMC; however, this rate decreased to 29% for those with scores > or = 10. One patient (4%) died from a cerebrovascular accident. Clinical follow-up at 1 year showed persistent clinical improvement in 89% of patients with an optimal result of BMC; 72% were in New York Heart Association class I and 17% in class II.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical trial of retrograde warm blood reperfusion versus standard cold topical irrigation of transplanted hearts

BACKGROUND A prospective, randomized clinical study involving 34 patients undergoing heart transplantation compared myocardial preservation of donor hearts maintained with continuous reperfusion with retrograde warm blood cardioplegia during surgical implantation versus the standard cold topical irrigation. METHODS Hearts in both groups were arrested with a standard crystalloid solution and maintained in a cold saline solution during transportation. In the retrograde group, cardioplegia was administered through a catheter in the coronary sinus during surgical implantation. An average of 471 +/- 30 mL of hyperkalemic crystalloid solution diluted 1:4 in warm blood from the oxygenator was infused. In the standard group, the heart was kept cold by topical irrigation of cold saline solution and was reperfused only when the ascending aorta was unclamped. RESULTS Preoperative characteristics of donors and recipients were similar in the two cohorts. Ischemic time average 139 +/- 12 minutes in the retrograde group compared with 130 +/- 11 minutes in the standard group (p = 0.57). Cardiopulmonary bypass time averaged 89 +/- 4 minutes in the retrograde group and 110 +/- 12 minutes in the standard group (p = 0.12). Defibrillation at reperfusion was performed in 4 patients (4/17, 24%) in the retrograde group and 12 patients (12/18, 67%) in the standard group (p = 0.01). There were no deaths in the retrograde group (0/17), whereas in the standard group, 3 patients (3/17) died of early graft failure (p = 0.11). Four early graft failures occurred in the standard group (p = 0.06). Two patients (2/17, 12%) were weaned from bypass with ventricular assist devices in the standard group. The number of subendocardial necrotic cells in the first two weekly endomyocardial biopsy specimens averaged 2.7 +/- 0.8 cells/mm2 in the retrograde group and 5.9 +/- 2.4 cells/mm2 in the standard group (p = 0.12). CONCLUSIONS Retrograde warm blood reperfusion appears to improve the initial recovery of transplanted hearts. The technique is easy to use and may be a useful approach to graft protection during surgical implantation.

Severe aortic regurgitation immediately after mitral valve annuloplasty

We report a case of severe aortic regurgitation occurring immediately after the insertion of a mitral annuloplasty ring. On transesophageal echocardiography, regurgitation was found to originate from the retracted left coronary cusp. On direct examination, part of the aortic wall was folded, but no suture could be identified. It was reasoned that tension created by the ring caused the retraction. The problem was corrected by releasing three sutures on the ring. Postoperative course was uneventful.

Cholesterol-lowering intervention and coronary artery disease after cardiac transplantation

Allograft coronary artery disease is a major threat to long-term survival after cardiac transplantation. It has been suggested that hyperlipidemia plays a major role in allograft coronary disease. The objective of the present study was to evaluate the effect of a lipid-lowering intervention with diet and drug therapy after cardiac transplantation. Forty-six patients who underwent transplantation between 1988 and 1991 and who were treated with the American Heart Association phase 1 diet and an HMG coenzyme A reductase inhibitor (lovastatin or simvastatin) when low-density lipoprotein cholesterol levels were higher than 3.4 mmol/L were compared with 35 untreated patients having transplantation between 1983 and 1988. Annual coronary angiograms were obtained in both groups. Cholesterol, triglyceride, and low-density lipoprotein levels were significantly lower in the treated group. Actuarial survival and event-free survival (survival free from allograft coronary artery disease) were similar in both groups. Low-density lipoprotein levels lower than 3 mmol/L at the last follow-up had a positive effect on event-free survival. The cholesterol-lowering intervention was not effective in decreasing the prevalence of allograft coronary artery disease. This study suggests that more aggressive measures to lower low-density lipoprotein levels may be necessary to significantly affect allograft disease. Clinical trials should be developed to address this hypothesis.