Demetre M. Nicoloff

Ten years' experience with the St. Jude Medical valve prosthesis

Records of 1,298 consecutive patients who had received the St. Jude Medical prosthesis were reviewed (713 male and 585 female patients; mean age, 61.79 +/- 13.4 years). Early mortality was 5.7% (74 patients). Ninety-three percent complete follow-up was accomplished for the 1,224 patients who left the hospital (4,306.50 patient-years). One hundred ninety-two of these patients died, a late mortality of 16.9%. Sixty-four patients experienced thromboembolic episodes (17 major and 35 permanent). Twenty-four patients had anticoagulant-related bleeding, 4 had valve thrombosis, 7 had prosthetic valve endocarditis, 9 had paravalvular leak, and 10 underwent reoperation. There was no structural valve failure in this series. Twenty-two of the 118 patients who had valve-related complications died; another 15 patients died of sudden and unknown causes. Therefore, the total number of valve-related deaths was 37. Of those patients who survived, New York Heart Association functional class improved significantly (98% in classes II and III preoperatively and 96% in classes I and II postoperatively). Linearized rates for thromboembolism, valve thrombosis, and anticoagulant-related bleeding were 1.49% +/- 0.19%, 0.09% +/- 0.05%, and 0.56% +/- 0.11%/100 patient-years, respectively. The actuarial estimate of incidence free from all complications, operative death, and valve-related death was 66.9% +/- 8.2% at the end of 9 years. In spite of old age and advanced heart disease, the patients who received the St. Jude Medical prosthesis had very good results over a 10-year period.

Does multivessel, off-pump coronary artery bypass reduce postoperative morbidity?

BACKGROUND Off-pump coronary artery bypass (OPCAB) is an emerging procedure. It is assumed that elimination of cardiopulmonary bypass for coronary artery bypass grafting has the potential for reducing postoperative morbidity. This review evaluates the safety and impact of multivessel OPCABG as compared to CABG. METHODS A retrospective review of 744 patients undergoing multivessel coronary artery bypass between January 1, 1997, and March 31, 1999, was done. The total population was divided into two groups: group A (n = 609 cardiopulmonary bypass) and group B (n = 135 OPCAB). This consecutive study cohort was elective status, full sternotomy with three or more distal anastomoses performed at a single institution. RESULTS The mean risk adjusted predicted mortality was 2.3% in group A and 2.7% in group B (p = NS), with the mean number of distal anastomosis being greater in group A (3.8 vs 3.5/patient, p < 0.001). Major postoperative complications were similar but were not statistically significant between groups. Postoperative blood loss and use of blood transfusions were the only significant variables (p < 0.001). CONCLUSIONS Multivessel OPCABG can be safely performed in selected patients. Elimination of cardiopulmonary bypass did not significantly reduce postoperative morbidity. Prospective randomized trials and long-term follow-up are needed to better define patient selection and the role of OPCABG.

Influence of Aspirin and Dipyridamole on Patency of Coronary Artery Bypass Grafts

A prospective randomized trial was performed to determine if the administration of inhibitors of platelet function would improve the patency of coronary artery bypass grafts. Patients were operated on for intractable angina with angiographically demonstrable lesions. The left internal mammary artery (IMA) was used for bypass of lesions of the left anterior descending coronary artery (LAD). Saphenous vein grafts were used for the LAD if the IMA was inadequate and for all other vessels. Treated patients received 1,300 mg of aspirin and 100 mg of dipyridamole (Persantine) orally each day. Control patients received neither drug. Patients returned 3 to 6 months after operation for repeat angiography. Results were analyzed by chi-square. One hundred seventy-four patients entered the study from June, 1973, through December, 1975, and 113 were analyzed. In the control group, 66 patients had 27 IMA-LAD grafts and 93 saphenous vein grafts. In the treatment group, 47 patients underwent 18 IMA-LAD grafts and 75 saphenous vein grafts. Ninety-eight of the 120 grafts (82%) were patent in the control group, and 87 of 93 grafts (94%) were patent in the treatment group (x2 = 6.34, p less than 0.02). Of the 45 IMA-LAD grafts in both groups, only 1 was occluded, a patency of 98%. In the control group, 72 of 93 saphenous vein grafts (77%) were patent. In the treatment group, 69 of 75 (92%) were patent (x2 = 6.54, p less than 0.02). The results of the study show a 15% difference between the two groups in the early patency of saphenous vein grafts. We continue to use aspirin and dipyridamole to improve the patency of saphenous vein bypass grafts.

Mini-sternotomy for coronary artery bypass grafting.

This communication details the approach to the left anterior descending artery, right coronary artery, or both via a single limited incision of the chest. The mini-sternotomy incision is 10 to 12 cm long. The distal anastomosis can be accomplished, with a beating heart, through this small incision, with or without cardiopulmonary bypass.

A new cardiac prosthesis: the St. Jude Medical cardiac valve: in vivo results.

SUMMARY The St. Jude Medical cardiac valve prosthesis is a low profile, lightweight, bi-leaflet, centralflow device constructed entirely of pyrolytic carbon. In vivo testing was performed in 24 cows in which the tricuspid valve (n = 14) or mitral valve (n = 10) was replaced by a St. Jude Medical prosthesis with a 26 mm tissue annulus diameter. Eight animals died in the operative period. The 16 surviving animals were sacrificed at 4, 8, 12, or 18 weeks. There were no valve-related deaths nor mechanical valve failures. Anticoagulation was not used in the postoperative period during which time monthly laboratory parameters were obtained including hemoglobin, hematocrit, white cell count, red cell count and indices, lactic acid dehydrogenase, serum haptoglobin, and, additionally at sacrifice, platelet and red cell morphology. Values indicated this prosthesis did not cause hemolysis. At sacrifice the pulmonary arterial tree and peripheral organs showed no evidence of thromboemboli. There was smooth endocardial ingrowth on all valve sewing rings. One valve had thrombus formation on the valve sewing ring. Nine animals were anesthetized prior to sacrifice and underwent open cardiac catheterization. Ventriculography (n = 6) showed minimal transvalvar reflux, and atriograms (n = 6) demonstrated central flow. Transvalvar gradients were 0 to 22 mm Hg (n = 9). One valve of an 18-week tricuspid implant was examined for wear: valve life was calculated to be greater than 2500 years. These data in conjunction with in vitro test results justify clinical trial of the St. Jude Medical prosthesis.

St. Jude Medical Prosthesis: Valve-Related Deaths and Complications

Despite the hemodynamic improvement in cardiac valve prostheses, valve-related deaths and complications have remained a substantial source of morbidity and mortality. This follow-up study was carried out in April, 1986, in a group of 816 patients who received 876 St. Jude Medical prostheses between October, 1977, and October, 1984. One hundred fifty-five patients (37%) of the 422 having aortic valve replacement (AVR) and 88 (29%) of the 300 having mitral valve replacement (MVR) had concomitant coronary artery bypass grafting, and 94 patients (12%) had miscellaneous procedures performed in addition to valve replacement. Sixty-three patients died within the operative period, an operative mortality of 7.7%. Follow-up was complete for 98% of the patients; the mean follow-up was 42 months. At that time, 87 more patients had died, a late mortality of 11.9%. There were 13 valve-related deaths (4 in the AVR group, 7 in the MVR group, and 2 in the miscellaneous group); the causes of death were thromboembolism (7), anticoagulant-related hemorrhage (2), valve thrombosis (2), prosthetic valve endocarditis (1), and perivalvular leak (1). There were 37 thromboembolic episodes (1.78/100 patient-years) and 67 anticoagulant-related hemorrhages (3.22/100 patient-years), 46% of which necessitated transfusion. The incidence of valve thrombosis was 0.6% (4 patients). Perivalvular leak and prosthetic valve endocarditis occurred in 7 patients (1.0%) and 5 patients (0.7%), respectively. Reoperation was carried out in 6 patients (0.8%), but only for perivalvular leak. There were no deaths, no complications, and no clinical evidence of malfunction of the prosthetic valve.(ABSTRACT TRUNCATED AT 250 WORDS)

Replacement of the aortic valve in patients under 50 years of age : long-term follow-up of the St. Jude Medical prosthesis

BACKGROUND Aortic valve replacement in the young adult (aged 18 to 50 years) is a choice between a mechanical prosthesis with attendant lifelong anticoagulation or biological prostheses of varying types that may have limited life expectancy in this age group. METHODS The Cardiac Surgical Research Foundation database was accessed to determine long-term outcomes in patients having aortic valve replacement with the St. Jude Medical Valve. This database has been privately maintained since the worlds first St. Jude Medical (SJM) valve implant in 1977. Patients were contacted by questionnaire or by telephone if the survey was not returned. Follow-up was 93% complete. RESULTS From October 1977 through October 1997, 271 patients less than 50 years of age had isolated aortic valve replacement. Follow-up was 1957 patient years. Thirty-day operative mortality was 1.1% with 18 late deaths, 4 of which were valve related. Ninety percent of survivor INR responses indicated a frequency of monthly INR checks or less. Valve-related events including percent per patient year and mortality related to these events included thromboembolism, 6 episodes (0.3% per patient year, no deaths); anticoagulant-related bleeding, 6 events (0.3% per patient year, 2 deaths); paravalvular leak, 6 events (0.3% per patient year, 2 deaths); valve thrombosis, 2 events (0.1% per patient year, no deaths); and endocarditis, 3 events (0.15% per patient year, no deaths). There was no incidence of structural valve failure. CONCLUSIONS The SJM valve has a long record of excellent performance with durability lasting more than 20 years. The incidence of untoward events is low and death over time due to valve-related complications is low (4 of 271). The SJM valve has become our valve of choice for younger patients.

Postoperative complete heart block in 64 children treated with and without cardiac pacing

Between 1957 and 1973, a total of 64 children had complete heart block during intracardiac surgery were treated by one of three methods: (1) No pacemaker: Six of the 13 patients in this group had reversion to sinus rhythm. Seven patients continued to have complete heart block, and five of these died of Stokes-Adams episodes. Two patients continue to have complete heart block without pacemaker insertion. (2) Temporary pacemaker: Seventeen of 25 patients had reversion to sinus rhythm and the temporary pacemaker was removed; the other 8 continued to have complete heart block. Five of the eight died--three of Stokes-Adams episodes and two at the time of cardiac reoperation. Three remain asymptomatic without placement of a permanent pacemaker. Six died of postoperative complications unrelated to heart block or pacemaker implantation. None of the other 20 experienced Stokes-Adams attacks. There was one late death in this group. Although there are problems in using permanent pacemakers and electrode systems, in these patients with operatively induced complete heart block their use was associated with a low mortality rate.

Minimally invasive direct coronary artery bypass grafting : Experimental and clinical experiences

BACKGROUND This communication briefly details the goals, indications, surgical approaches, and limitations of minimally invasive direct coronary artery bypass grafting (MIDCABG). The experimental experiences from various institutions are summarized. METHODS The clinical experiences of 72 consecutive MIDCABG procedures performed at our institutions between June 5, 1995, and August 13, 1996, were analyzed. We have divided patients into two groups. Group A consists of healthy low-risk patients with single lesions of the left anterior descending coronary artery or the right coronary artery, or with both lesions of both arteries. Group B consists of high-risk patients who had major contraindications to conventional cardiopulmonary bypass procedures. There were 55 patients in group A and 17 patients in group B. Using The Society of Thoracic Surgeons preoperative predicted risk module, group A had a 1% predicted mortality versus 4% in group B. RESULTS The 30-day mortality was 2% in group A and 6% in group B. The mean postoperative length of stay was 4 days for group A and 5 1/2 days for group B. Short-term follow-up of the survivors appears promising, and 81% of patients were angina free at the time of last follow-up. CONCLUSIONS The MIDCABG techniques are still developing. The short-term results during the learning period appear to be quite good, but long-term results remain yet to be seen. The addition of new equipment to facilitate construction of the anastomosis will enhance application and results. The lessons learned from these approaches are already being applied to other areas of cardiac surgery including valve replacement and the repair of congenital heart defects.

Opposite trends in coronary artery and valve surgery in a large multisurgeon practice, 1979–1999

BACKGROUND Trends in coronary artery bypass (CAB) and valve operations (VO) may help predict the future of cardiac surgery in the context of changing case mix, shifting paradigms, emerging technology, and population demographics. METHODS We retrospectively reviewed all 30,319 adult CAB and VO in our group from 1979 to 1999 according to specific procedures. RESULTS Coronary artery bypass volumes peaked in 1996 at 1,895 cases, declining 15.3% to 1,605 cases in 1999 with a decrease in risk profile and percent reoperations and an increase in mean age and percent octogenarians, prior percutaneous coronary interventions (PCI), left internal mammary artery (LIMA) graft usage, off-pump technology usage, and hospital mortality of reoperations. Right internal mammary grafts were employed infrequently and radial artery grafts transiently. Overall VO volumes continued to increase 24.0% since 1996, from 470 to 583 cases with a decreased risk profile, increased mean age, and percent octogenarians and prior PCI. The percentage of mechanical valve implants decreased, while the percentage of various tissue solutions for valve disease increased. Limited access incisions and port-access were employed transiently with CAB and VO. CONCLUSIONS Coronary artery bypass volumes are decreasing, with an increasing percentage of LIMA grafts and off-pump cases. Valve operation volumes are steadily increasing, with a decreasing percentage of mechanical valve implants, in favor of various tissue solutions.