Biomedical subjects
Publications and source records attributed to V Velebit.
We present, with echocardiographic and intraoperative findings, a rare case of left ventricular-to-right atrial communication (Gerbode defect) after endocarditis associated with Staphylococcus aureus. (Tex Heart Inst J 1995;22:100-2)
In recent years coronary artery bypass grafting (CABG) has been extended to include patients with very low left ventricular ejection fractions (LVEF), also frequently with co-existing mild to moderate mitral valve regurgitation (MR). The question is, should such a MR be corrected simultaneously with a myocardial revascularization or not? Between January 1989 and November 1994, 56 patients with preoperative LVEF < or = 25% and echocardiographic evidence of co-existing MR (Grade I: 41%, II: 46%, III: 13%) underwent primary CABG. None of them had simultaneous mitral valve surgery. Twenty-nine patients (52%) had a pulmonary artery pressure (PAP) > 40 mmHg. The mean preoperative LVEF was 17.9 +/- 4.6 (10-25), mean PAP 44.2 +/- 16.1 mmHg. An average of 4.5 +/- 1.5 grafts/patient were placed and five patients had simultaneous repair of a post-infarction left ventricular aneurysm. The overall mortality was 3.6% (2/56). Transient post-operative low cardiac output syndrome occurred in 16 patients (29%). Twenty-one patients (38%) had no postoperative complications at all. The 54 hospital survivors were followed up over a mean period of 12 months (3-36 months). There was one death (eight months postoperatively) and two graft occlusions, not requiring reoperation. At the end of the follow up echocardiography showed that 50 patients (93%) had no (31 patients) or only a very mild Grade I MR (19 patients). Four patients had Grade II MR, none of them requiring mitral valve surgery. All patients improved their NYHA functional class, from 3.4 +/- 0.8 to 1.9 +/- 0.7 and LVEF from 17.9 +/- 4.6 to 44.2 +/- 7.4 (p < 0.001). Coronary artery bypass grafting is a possible treatment for patients with very low LVEF, provided the patient has a two- or three-vessel disease with significant coronary artery stenosis (> 70%) and angina. Mortality and morbidity are low. Moderate co-existing MR (Grade I-III) seems to normalize after myocardial revascularization and should not be surgically corrected therefore at the primary operation.
In order to identify peroperative risk factors and to evaluate different etiological factors in developing postoperative gastrointestinal complications, clinical variables were studied in 3493 patients undergoing adult cardiac surgery. There were 86 gastrointestinal complications, 2.9%, with an overall morality among these of 22.1%: the mortality rate was 3.9% for all patients undergoing cardiac surgery at our institution (p < 0.001). Paralytic ileus, intestinal ischemia, and acute cholecystitis were the most frequently seen complications. Arterial hypertension, smoking and poor preoperative cardiac function, clinical instability, and the need for an emergency operation were distinct clinical risk factors. Cardiopulmonary bypass time was, by itself, not an important factor. Embolic etiology was also ruled out. The incidence of peroperative myocardial infarction, low postoperative cardiac output necessitating massive use of vasopressor substances and/or intraaortic balloon pumping were significantly more often observed in patients who subsequently developed gastrointestinal complications. The common etiological factor in developing gastrointestinal complications of any kind, after cardiac surgery, seems to be postoperative splanchnic hypoperfusion with visceral ischemia. In order to reduce postoperative morbidity and mortality it is essential to identify patients at risk, support preoperative poor cardiac function, and to carefully monitor these patients postoperatively for abdominal complications to reach an early diagnosis.
Fourty-seven patients with a least one heart valve operation each who underwent reoperations (Gr. I) were analyzed with special regard to risk factors influencing the perioperative mortality and compared to 203 patients operated for the first time (Gr. II) during the same time period. Mean age was 57.1 years in Gr. I and 64.1 years in Gr. II (p < 0.05). There were no differences between the groups with regard to sex, smoking, obesity, or concomitant peripheral vascular disease. Hypertension, hyperlipidemia, and diabetes were more frequently seen in Gr. I, p < 0.05. A significantly higher number of patients in the redo group (Gr. I) belonged preoperatively to NYHA class III or IV, p < 0.001 and needed emergency surgery more often, p < 0.01, but left-ventricular function did not differ between the groups. There was no significant difference in the position of valves operated or the number of multiple valve replacements/repairs between the groups, and no difference in aortic cross-clamping or cardiopulmonary bypass time. Most patients were referred from other hospitals. Overall perioperative mortality for Gr. I was 6.4% and Gr. II 4.4% (n.s.). Mortality after first reoperation was 5.0%, after second or more 14.3%. Perioperative mortality was related to age, preoperative NYHA class, and urgency of operation in both groups, and to multiple valve replacement/repair in Gr. I. Elective reoperation carried a mortality of 4.8% but emergency reoperation 20%; reoperation mortality was 2.6% for single valves and 25% for multiple valves.(ABSTRACT TRUNCATED AT 250 WORDS)
AIM AND METHODS: Data from patients younger than 75 years (group I, n = 2939) and patients aged 75 years or older (group II, n = 111) who underwent isolated coronary artery bypass grafting (CABG) during a 9-year period (January 1984 to April 1993) were analyzed to determine comparative risk factors for morbidity, early and late survival, and functional outcome. RESULTS: Traditional risk factors (hypertension, hyperlipidemia, diabetes mellitus, and smoking) were significantly more prevalent in group II. The number of patients in New York Heart Association (NYHA) functional classes 3 and 4 before surgery was also significantly higher in group II (P < 0.001), but emergency operations were equally distributed between the groups. Left main-stem stenosis was more frequent in group II patients (P < 0.01), while the number of vessels involved and pre-operative left ventricular function did not differ. Both groups underwent a mean of 4.5 grafts. Internal mammary grafts were placed in 48.4% (1422/2939) in group I and 19.8% (22/111) in group II (P < 0.001). The overall peri-operative mortality rate did not differ between the groups (2.9% for group I and 2.7% for group II). Non-fatal peri-operative myocardial infarction, ventricular arrhythmias, post-extracorporeal circulation disorientation, and temporary renal insufficiency were more prevalent in group II patients (all P < 0.05). Emergency operations and re-operative CABG increased the peri-operative mortality in both groups. The 3-year survival rate was 93% and the 3-year cardiac event-free rate was 88% for the group II patients. Most of the elderly patients (98%) were in NYHA functional classes 1 and 2 at the end of the follow-up. CONCLUSIONS: Even if elderly patients have a slightly higher postoperative morbidity than younger patients, and an increased mortality if operated upon in an emergency, long-term survival and freedom from cardiac events are excellent and justify the continued performance of CABG in patients aged 75 years of age or more.
Replacement of the ascending aorta for aneurysm or dissection remains a complex challenge for cardiac surgeons. Between January 1984 and December 1993, 30 patients have had simultaneous resection of the ascending aorta and aortic valve replacement. Sixteen of them had composite graft replacement of the ascending aorta and the aortic valve with a modified Bentall's technique (Group I). Fourteen patients had supracoronary artery aortic resection and aortic valve replacement (Group II). The mean age was 50.1 +/- 15.3 years (range 23-76). There were 22 men and 8 women. Five patients (16.7%) had aortic dissection, six were operated on an emergency basis. Concomitant coronary artery disease was more frequently seen in Group II (5 patients) than in Group I (1 patient), p < 0.05. Other preoperative patient characteristics did not differ. The overall perioperative mortality was 16.7% (5/30), none of them due to technical complications during surgery. Four patients died in Group I and 1 in Group II (n.s.). Non-fatal myocardial infarction was diagnosed in 1 patient (Group I) and only one neurological complication occurred (Group I), while reexploration for bleeding was performed in 4 cases (13.3%). Four patients in Group I and two in Group II had postoperatively low cardiac output, two of them necessitating intraaortic balloon pump insertion. 43% of the patients had no perioperative complications. At the end of follow-up (n = 25), average 6 months (range 1-52 months), twenty-two survivors (22/25 or 88.0%) were in NYHA functional class 1. Simultaneous ascending aortic aneurysm repair and aortic valve replacement can be accomplished with an acceptable mortality and little morbidity.
A consecutive series of 2645 patients underwent primary coronary bypass grafting while 458 patients underwent reoperative bypass during a 9-year period. The mean age (61 years), sex distribution (83% men) and preoperative risk factors were identical in the two groups. Significantly more patients belonged to New York Heart Association (NYHA) class 4 and were clinically unstable in the reoperative group (P < 0.001). The internal mammary artery was used in 43% of the single operation group but in only 23% of patients who subsequently required reoperation (P < 0.001). In reoperations 61% of the patients had an internal mammary artery graft (P < 0.001). The overall operative mortality rate for single operation was 2.3% (62/2645) versus 9.2% (42/458) for reoperations. Patients with a reoperative interval of more than 1 year had a 8.4% mortality rate, compared with 28% in those reoperated on 1 year or less after the initial operation (P < 0.01). Preoperative myocardial infarction, intra-aortic balloon pump insertion, prolonged ventilatory support and ventricular arrhythmias were all prevalent after reoperations (all P > 0.001), while postoperative myocardial infarctions and re-sternotomy for bleeding did not differ between the groups. Emergency operation, preoperative NYHA class 3-4 and poor left ventricular function were predictors of perioperative mortality in both groups. Left main stem stenosis was an added factor in the reoperative group. After reoperation 93% of the hospital survivors were alive at 5 years after surgery; the cardiac event-free rate was 59% and > 90% of the patients showed improvement of their NYHA class during the follow-up. Reoperative coronary artery bypass grafting is effective, but has an increased operative mortality and morbidity, especially in patients with unstable angina, left main stem stenosis and poor preoperative left ventricular function.
In order to evaluate the potential risks of a patent internal mammary artery bypass at reoperative coronary artery bypass grafting, we have reviewed the records of 233 consecutive patients undergoing reoperative coronary artery bypass grafting between 1 January 1991 and 31 December 1993, including 209 patients having an occluded mammary graft or no mammary graft (Group I) and 24 patients having a patent mammary graft (Group II). With regard to preoperative patient characteristics, the only significant differences between the groups were: Group II patients had a higher preoperative left ventricular ejection fraction than did Group I patients (63.7% +/- 8.9% vs. 52.1% +/- 10.1%, p < 0.001); and Group II patients had received fewer grafts per patient than had patients in Group I (2.2 +/- 1.1 vs 3.6 +/- 1.4 grafts per patient, p < 0.001). There were no entry injuries to the grafts or to the heart in either of the groups. No perioperative mortality was encountered in Group II, while 11 patients died in Group I (p < 0.05). Group II had a significantly higher incidence of reexploration for post-operative bleeding, whereas Group I had a significantly higher incidence of low postoperative cardiac output. The incidence of all other perioperative complications did not differ between the groups. The results of this study support the use of mammary grafts even in patients who are likely to need repeat coronary artery bypass grafting and certainly does not disqualify such patients from a 2nd operation.
Clinical variables were studied in 3129 patients undergoing coronary artery bypass grafting to identify patients at risk of abdominal complications and common etiologic factors in the development of such complications. Seventy-three gastrointestinal complications occurred (2.3%), with an overall mortality rate of 16.4% compared with a mortality rate of 3.4% for all patients undergoing bypass grafting (p < 0.001). Cholecystitis and intestinal ischemia were the most frequently encountered complications. Multivariate analysis demonstrated that preoperative hypertension, New York Heart Association classes III and IV, preoperative left ventricular ejection fraction less than 40%, age greater than 70 years, reoperation, and urgent operation as independently and significantly associated with gastrointestinal complications. In contradiction to previous reports, no significant correlation existed between gastrointestinal complications and cardiopulmonary bypass time, 99.8 +/- 35.8 versus 101.2 +/- 39.8 minutes. Perioperative myocardial infarction and immediate postoperative hypotension with low cardiac output necessitating substantial inotropic pharmacologic support or intraaortic balloon pumping were significantly more prevalent in patients who had gastrointestinal complications (all p < 0.001). Furthermore, multivariate analysis revealed that postoperative low cardiac output was a significant, independent predictor in the development of gastrointestinal complications of any kind after coronary artery bypass grafting. Postoperative splanchnic hypoperfusion could therefore be a common etiologic factor.
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Allograft coronary artery disease (CAD) is the major determinant of long-term survival following heart transplantation (HTx). In a group of 210 heart transplant recipients, we diagnosed CAD in 54 (27.1%) by coronary angiography, postmortem examination or examination of the transplanted heart at the time of retransplantation. Retrospective analysis of potential risk factors for the development of CAD was performed for both immunological (rejection pattern, immunosuppressive therapy, cytomegalovirus [CMV] infection), and nonimmunological (hyperlipidemia, smoking, hypertension, diabetes mellitus, obesity) risk factors. The total number of rejection episodes correlated significantly with the occurrence of CAD (P less than 0.05), showing that patients who experienced two or more rejection episodes had an incidence of CAD of 40%, as opposed to a 23% incidence in patients who experienced no rejection. A composite rejection score derived from multivariate regression analysis of the severity, frequency, and timing of acute cardiac rejection episodes was found to correlate with the development of CAD (P less than 0.05). Postoperative arterial hypertension also correlated significantly with the onset of CAD (P less than 0.01), with a 92.6% incidence of hypertension in the group with CAD versus 76.3% in the group without CAD. Smoking after transplantation correlated significantly with the occurrence of CAD (P less than 0.05). There was no significant correlation with other analyzed factors in this group of patients. In this review, the development of CAD after heart transplantation correlated with treated allograft rejection. Aggressive treatment of hypertension and cessation of smoking may contribute to alleviation of this serious complication.
Techniques for implantation of the Hemopump, an intraarterial, axial-flow circulatory assist device, are described. The Hemopump, which is currently undergoing clinical investigation, has been used successfully to treat patients experiencing profound left ventricular failure in a variety of clinical situations, including postcardiotomy shock, acute myocardial infarction, cardiac allograft rejection, and cardiac allograft failure.
In 500 consecutive procedures of elective coronary angioplasty attempted at a centre with a primary success of 86%, one or more major acute complications occurred in 34 cases (6.8%). Twenty four patients (4.8%) sustained an acute myocardial infarction (in six this was despite emergency coronary artery bypass surgery) and two patients (0.4%) had emergency coronary bypass without myocardial infarction. Ventricular fibrillation was a complication without sequelae in five (1.0%) patients; one (0.2%) patient died because of refractory ventricular fibrillation and ensuing electromechanical dissociation. "Benign" coronary artery rupture occurred in one (0.2%) patient, and one (0.2%) patient had elective coronary surgery to retrieve the tip of a fractured guide wire after an otherwise successful angioplasty. Despite a low mortality, coronary angioplasty is associated with major complications in about one of 14 procedures; the complication is usually acute myocardial infarction caused by occlusion of the vessel.
Over the last years disposable systems have replaced in many hospitals the glass bottle drainage equipment used after cardiac surgery. The present study was designed to evaluate the incidence of postoperative infections and technical problems with 2 types of drainage systems. Positive microbial cultures and infectious complication as well as technical incidents were lower with the disposable equipment. The costs of the material alone, when infections are not taken into consideration, are slightly lower for the glass drainage system. We conclude from this survey that the incidence of superinfection of a closed, disposable system for mediastinal drainage is rare and smaller than with conventional glass bottles. When costs of different systems are compared, this consideration may be important.
To evaluate medium-term clinical results of two major methods of myocardial revascularization, we compared 80 consecutive patients with multivessel percutaneous transluminal coronary angioplasty (PTCA) with 80 consecutive patients with coronary surgery using both internal mammary arteries in all and additional venous grafts in some. Patients in the surgical group had a higher extent of coronary artery disease. In patients with PTCA a mean of 2.2 vessels per patient were attempted, and in patients with surgery 2.7 distal anastomoses per patient were performed. Primary success for PTCA and surgery was 86% vs 94% and complications occurred in 7% vs 6%, respectively. Control angiograms, done in 86% of patients (59/69) after successful PTCA, showed a recurrence in 42% (25/59). Repeat PTCA was done in 15, elective surgery in seven, and a medical treatment was pursued in 3% patients with restenosis. Recurrence of symptoms after successful surgery was found in three patients (4%). They were treated with PTCA. Clinical follow-up was available for all patients, at a mean of 12 +/- 6 months after PTCA and 16 +/- 9 months after surgery. Mean improvement was 1.5 NYHA functional classes after successful PTCA and 2.1 after surgery; 60% (48/80) vs 89% (48/80), respectively, were in class I (p less than .0001). There were fewer PTCA patients than surgical patients without antianginal drugs at follow-up (19% [11/58] vs 37% [18/48]; p less than .05), and their double product during exercise testing was inferior (272 +/- 56 vs 295 +/- 47 mm Hg X beats/min/100; p less than .05). Medium-term clinical outcome appears better after successful surgery with both internal mammary arteries than after successful multivessel PTCA.
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Exercise performance after implantation of the pacemaker with physical activity dependent pacing rate (Activitrax, Medtronic) was assessed by treadmill tests one month afterwards in 10 patients and a further 6 months later in 6 of them, who had long been VVI pacing dependent (reimplantation subgroup). In the 1 month test exercise performance had improved in 7 of 10 in activity pacing mode compared to VVI mode. After 6 months of physical activity dependent pacing the patients in the reimplantation subgroup showed an improved exercise test in VVI mode compared to the 1 month test in VVI mode. In activity pacing mode there was an additional improvement (increase of exercise duration from 12.1 +/- 2.5 to 14.5 +/- 2.7 min, p less than 0.005, and of accumulated work from 31.1 +/- 15.1%, p less than 0.002) compared to the VVI mode. Since Activitrax PM allows better exercise performance at longterm follow-up, it becomes a pacing mode of choice when double chamber pacing is impossible.