Analysis of risk factors for excess mortality after aortic valve replacement.

OBJECTIVES: This study sought to identify risk factors for both late observed and late "excess" mortality after aortic valve replacement and to examine the causes of late mortality. BACKGROUND: Because operative mortality after aortic valve replacement is very low, the timing of surgical intervention should focus on maximizing long-term survival. However, to judge the effect of valve replacement on long-term survival in an elderly population, it is important to separate mortality resulting from extraneous causes (background mortality) from disease-related mortality (excess mortality). Background mortality can be estimated by calculating expected mortality on the basis of age and gender. METHODS: From 1966 to 1986, 643 patients (mean age 59.6 years, 138 [21%] > or = 70 years old) underwent aortic valve replacement, 129 of whom also underwent coronary bypass grafting; 594 patients survived > or = 30 days after the procedure. The overall operative mortality rate for isolated aortic valve replacement decreased over time from 25.5% (1966 to 1972) to 2.6% (1980 to 1986). Cumulative total follow-up after discharge was 3,603 patient-years. Multivariate analysis was performed for both observed and excess mortality. RESULTS: Risk factors for both observed and excess mortality were previous myocardial infarction, coronary artery disease, heart failure and atrial fibrillation. Although age > or = 70 years was a risk factor for observed mortality (hazard rate ratio [HRR] 2.4, 95% confidence interval [CI] 1.6 to 3.7), it was not a risk factor for excess mortality. In contrast, isolated aortic regurgitation was an important risk factor for excess mortality only (HRR 3.8, 95% CI 1.3 to 11.2). Late mortality was valve related in 22% of patients, including sudden death in 7% and cerebral vascular accidents in 7%. Congestive heart failure was an important cause of death (21%) irrespective of the time elapsed since aortic valve replacement. In patients with aortic regurgitation, congestive heart failure was the main cause of death (38%); in patients with aortic regurgitation and preoperative heart failure or severe left ventricular dysfunction, heart failure was the cause of death in 44% and 63%, respectively. CONCLUSIONS: Analysis of excess mortality revealed that older age in itself is not a risk factor for late mortality after aortic valve replacement. Aortic regurgitation carries a high risk, probably associated with left ventricular dysfunction at the time of operation. Earlier operation may be warranted in such patients.

Screening for solid organ malignancies prior to heart transplantation.

BACKGROUND: Prognosis of solid organ cancer in immunosuppressed hosts is generally dismal. Therefore, every effort to identify patients with asymptomatic carcinomas before transplantation should be encouraged. METHODS: Sixty-seven patients referred for heart transplantation were examined adhering to the scheme proposed at the 24th Bethesda Conference. To increase the sensitivity of this work-up, the following items were added: tumor marker assays (prostate-specific antigen in males, carcino embryogenic antigen), abdominal ultrasound, CT scan of the abdomen and the thorax, mammography/echography of the breasts, PAP smear, colonoscopy if carcino embryogenic antigen abnormal or occult blood in stool, prostate echography if prostate-specific antigen abnormal or prostate hypertrophy. RESULTS: Carcinoma was detected in 10 of the 67 patients; for 8 patients of this cancer group, transplantation was denied. Importantly, 9 of the 10 malignancies were detected by means of the diagnostic items that were added to the standard screening protocol. There were no significant differences between the cancer and the non-cancer group regarding mean age, sex, etiology of heart failure, and smoking history. Stratifying patients in younger (i.e., < or =54 years) and older (i.e., > or =55 years) age groups showed a significantly greater proportion of older patients in the cancer group (8/10=80%) compared to the non-cancer group (25/57=44%), P=0.04. After a mean follow-up of 34 months, 5 of the 36 transplanted patients developed a malignancy (4 skin carcinomas, 1 non-Hodgkin lymphoma). There have been no malignancy-related deaths until now. CONCLUSION: The importance of a thorough screening program in the triage of candidates with preexisting malignancies, especially in an older patient population, is illustrated in this report.

Late results of 200 repeat coronary artery bypass operations.

To determine the clinical outcome and the long-term results of a second coronary artery bypass operation, we studied preoperative clinical status and catheterization data in 200 consecutive patients over a 9-year period (1979 to 1987) (mean follow up time 34 months, maximum 120). The study group included 169 men and 31 women (mean age 58.4 years [7% greater than 70 years]). Sixty-four percent of patients had severe angina (New York Heart Association class IV), 70% had 3-vessel coronary artery disease and 21% had poor left ventricular function. Reoperation was performed after a mean interval of 58 months after the first procedure. A mean of 3.3 distal anastomoses was placed. The operative mortality rate (30 days) was 7.5%, with additional cardiac morbidity (myocardial infarction, heart failure) in 11.5% of patients. Multivariate analysis showed an increased risk in women (risk ratio 3.6) and in patients with poor left ventricular function (risk ratio 3.1). The cumulative 5-year survival rate was estimated at 84%, with a rate of 77% for patients with poor left ventricular function (difference not significant). The probability of remaining free of a cardiac-related event (myocardial infarction, angioplasty, third operation, cardiac death) was 64% for 5 years. At the end of follow-up, 79% of the surviving patients were in New York Heart Association class I or II and nearly 50% of patients in the fifth year after the reoperation had good functional status. It is concluded that a reoperation is effective but carries an increased, immediate, operative risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of changes in management of active infective endocarditis on outcome in a 25-year period.

The clinical outcome and long-term follow-up of 130 consecutive patients (141 episodes) with active infective endocarditis who were treated between 1966 and 1991 were analyzed. There was a shift toward a higher proportion of referred patients (39 to 78%), patients aged > 60 years (11 to 41%) and urgent surgical treatment (11 to 44%). Medical treatment was administered in 98 patients (70%); 30-day mortality was 27%. Surgery was performed in 43 patients (30%), with an operative mortality of 26%; 9 of 14 patients (64%) who underwent operation within the first week of admission died. Patients with severe heart failure are at the highest risk for early mortality (relative risk = 21.1; 95% confidence interval 7.4-60.3). Referred patients were much more often treated surgically than were nonreferred patients (48 versus 14%) and had a lower operative mortality (24 vs 30%). Nonreferred patients were more often treated medically (86 vs 52%) and with lower mortality (19 vs 39%). The total follow-up time was 730 patient-years; only 1 patient was considered lost to follow-up. The overall cumulative 5-year and 10-year survival after hospital discharge for patients after urgent surgery were 84 +/- 7% and 53 +/- 7%, respectively, and for those after medical treatment 84 +/- 5% and 77 +/- 6%, respectively. The probability of remaining free of late events (recurrent endocarditis, late valve replacement or death) during 5 and 10 years for patients after urgent surgery was 84 +/- 7% and 53 +/- 15%, respectively, and for those after medical treatment 59 +/- 6% and 40 +/- 7%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of left ventricular aneurysm resectability by two-dimensional echocardiography.

Mortality of surgical resection of a left ventricular (LV) aneurysm is largely determined by size and function of nonaneurysmal or residual myocardium. A residual myocardial index was determined using 2-dimensional echocardiography (2-D echo) in 56 consecutive patients scheduled for LV aneurysmectomy, and these results were correlated with surgical outcome. The index was calculated using 3 apical cross sections: the 2- and 4-chamber views and the long-axis view. These views were recorded at mutual angles of 60 degrees. In each view the end-diastolic length of normally moving endocardium of the 2 opposite walls was expressed as a fraction of the end-diastolic LV long axis. The index was assessed by averaging the 6 ratios obtained. In 41 survivors the index ranged from 40 to 71% (mean +/- standard deviation 53 +/- 7.8) and in 15 nonsurvivors from 29 to 67% (mean 38 +/- 8.5, p less than 0.01). With 1 exception, this echocardiographic index sharply separated survivors from nonsurvivors. The lower limit to survive aneurysmectomy was 40%.

Antihypertensive and anti-ischemic effects of nicardipine and nitroprusside in patients undergoing coronary artery bypass grafting.

The efficacy of nicardipine vs nitroprusside in controlling hypertension after sternotomy was compared in 120 patients undergoing coronary artery bypass grafting and anesthetized with fentanyl (100 micrograms/kg). All had good left ventricular function and had been receiving long term oral beta-blocking therapy. Patients were randomly allocated to 1 of 3 groups: group C, the control (n = 40), received no vasodilator; group N (n = 40) received intravenous nicardipine at an initial rate of 3 micrograms/kg/min; and group S (n = 40) received intravenous nitroprusside at an initial rate of 1 microgram/kg/min. Vasodilator infusion was begun before surgery and infusion rates were adjusted to maintain systolic blood pressure between 80 and 120% of postintubation (baseline) values. Additional measurements were obtained before incision and after sternotomy. In groups N and S, arterial blood pressure was effectively controlled in all patients. Before the incision, pulmonary artery pressure decreased in group S and systemic vascular resistance decreased in groups N and S. After sternotomy, mean arterial pressure, heart rate, pulmonary artery pressure, pulmonary capillary wedge pressure, cardiac index and rate-pressure product increased in group C. At this time, pulmonary artery pressure returned to baseline values in group S. In groups N and S, heart rate, cardiac index and rate-pressure product increased, but, compared with baseline values, systemic vascular resistance remained low after sternotomy. Ischemic changes were seen in the electrocardiogram in 11 patients (28%) in group C, 10 patients (25%) in group S and 4 patients (10%) in group N. The concentration of creatine phosphokinase MB was not significantly different in the first 24 postoperative hours in any group.

Nonfebrile mitral valve endocarditis due to Neisseria subflava.

Native valve endocarditis normally presents with fever and only later in its course demonstrates dysfunction of the affected valve. We describe a case of endocarditis due to Neisseria subflava, a Gram-negative diplococcal saprophyte of the oral cavity, which was unsuspected clinically and found unexpectedly during a mitral valve operation performed for symptomatic prolapse with regurgitation.

Right-to-left flow through a patent foramen ovale in acute right ventricular infarction. Two case reports and a proposal for management.

Right-to-left shunting through a foramen ovale complicating acute right ventricular infarction and resulting in severe arterial hypoxemia has been described eight times before. Treatment strategies have often aimed at reducing the shunt. Four patients died. Less attention has been paid to attempts at revascularization and, despite a high incidence of atrioventricular conduction disturbances, to temporary dual-chamber pacing. We describe herein two patients with postcardiac surgical right ventricular infarction complicated by severe right-to-left interatrial shunting. Treatment strategy was aimed at improving right ventricular function, and right-to-left shunting ceased. All efforts should be directed at treating right ventricular dysfunction, which is the cause of the clinical picture, and not at reducing the shunt, which is a secondary phenomenon.

Spontaneous dissection of three major coronary arteries subsequent to cystic medial necrosis.

This case report describes the devastating consequences of spontaneous coronary dissection in a 36-year-old female patient. Surgical revascularization was attempted, but diffuse myocardial infarction developed. The patient was bridged to heart transplantation but died secondary to multiple organ failure. To our knowledge, this is the only reported case of spontaneous dissection of the three main coronary arteries due to severe cystic medial necrosis.

Intraoperative transesophageal color-coded Doppler echocardiography for evaluation of residual regurgitation after mitral valve repair.

Because mitral valve competence after mitral valve reconstruction is awkward to assess during this procedure, we evaluated in this respect transesophageal color-coded Doppler echocardiography in 23 patients undergoing mitral valve reconstruction for severe mitral regurgitation. Transesophageal echocardiographic examinations were performed after induction of anesthesia but before sternotomy (baseline), after mitral valve repair before decannulation, and at sternal closure, all at similar mean aortic pressure and echocardiographic instrument settings. The degree of mitral regurgitation by transesophageal color Doppler flow mapping was visually quantified on a 5-point scale (0 to 4), pending the left atrial extent of the regurgitant jet. This was compared with the degree of mitral regurgitation by left ventricular cineangiography performed within several weeks after operation and also visually quantified on a 5-point scale (0 to 4), with use of the right anterior oblique projection. There was good correlation between the two methods (r = 0.83; p less than 0.001). We conclude that residual mitral regurgitation, as assessed by transesophageal color flow mapping in the operating room, highly correlates with the ultimate mitral regurgitation by cineangiography. Therefore transesophageal echocardiography can be helpful for evaluation of mitral valve competence during mitral valve reconstruction, and hence, in case of repair failure, allow valve replacement in the same surgical session, thus avoiding reoperation.

Primary cardiac allograft failure after donor carbon monoxide poisoning treated with biventricular assist device.

Because of the current donor shortage, organ selection criteria are being progressively liberalized. We present a case of carbon monoxide poisoning in a multiorgan donor that led to primary cardiac allograft failure. A biventricular assist device was used as a bridge to recovery.

Myocardial protection with cold cardioplegia in a patient with cold autoagglutinins and hemolysins.

A technique is described for providing myocardial protection with cold potassium crystalloid cardioplegia in a patient with cold autoagglutinins and hemolysins. The patient was only mildly cooled systemically. The coronary system was perfused with a normothermic cardioplegic solution to remove the blood before the cold cardioplegia was started. The heart was rewarmed with a normothermic cardioplegic solution before the blood was reintroduced. With this technique, the patient underwent an uneventful coronary bypass operation.

Biventricular assist for severe acute rheumatic pancarditis.

Severe heart failure in acute rheumatic myocarditis is rare. It may be rapidly reversible with treatment, so maximal medical treatment and, if necessary, mechanical support should be given before heart transplantation is considered.

How soon should drainage tubes be removed after cardiac operations?

Pericardial effusion frequently occurs after cardiac operation. Despite its high incidence, the etiological process of postoperative pericardial effusion remains unclear. Residual blood or thrombus has often been suggested as a possible cause, implying that the occurrence of pericardial effusion could be related to the effectiveness of postoperative thoracic drainage. This possible relationship, however, has never been studied. We found that prolonging the duration of thoracic drainage by 24 hours often increases total chest tube output considerably but does not affect the incidence of postoperative pericardial effusion: approximately 55% of 100 patients in this study were shown by two-dimensional echocardiography to have pericardial effusion on the sixth postoperative day, regardless of the duration of postoperative drainage. Because of this, and because a long period of drainage causes discomfort for the patient, mechanical irritation to the heart and the pericardium, and an increased risk of infection, we recommend removing drains as soon as their efficacy has peaked, preferably on the first postoperative day.

Intraoperative assessment of the mitral valve: transesophageal Doppler echocardiography vs. left ventricular filling of the flaccid heart.

Several methods can be used for the intraoperative assessment of residual mitral regurgitation (MR) following reconstruction of the mitral valve. The aim of this study was to compare the reliability of two of these methods: left ventricular filling of the arrested heart with saline (LVF) and intraoperative transesophageal Doppler echocardiography (TEE). Reliability was assessed by comparing LVF and TEE to postoperative left ventricular angiography (LVA) in 27 patients. LVF, TEE and LVA grading of MR was 0-4. Correlations, as measured by the Kappa statistic, were as follows: LVF-LVA: K = 0.33 (95% confidence interval (CI): 0.06-0.59), TEE-LVA: K = 0.48 (95% CI: 0.20-0.77), LVF-TEE: K = 0.43 (95% CI: 0.20-0.67). Considering LVF and TEE as predictors of LVA gradings above 2, sensitivities were 0.4 and 0.6, respectively. Specificities were 1.0 for each method. In conclusion, we found TEE in the beating heart not to be significantly more reliable in the prediction of residual MR than LVF in the flaccid heart.

Veno-venous bypass without systemic heparinization using a centrifugal pump: a blind comparison of a heparin bonded circuit versus a non heparin bonded circuit.

Veno-venous bypass without the use of systemic heparinization has recently become of increasing interest for application during liver transplantation and surgery on the large abdominal veins. However, possible adverse effects on blood components as demonstrated by means of hematologic and hemostatic parameters or on the occurrence of thromboembolic complications are until now not excluded. No consensus has been reached as to the efficacy of heparin coated circuits in those procedures. In the present study veno-venous bypass was performed for four hours in ten dogs using heparin coated and non coated circuits without further heparinization in a randomized blind fashion. No changes or significant intergroup differences were noted in the hematological and coagulation parameters. Macroscopic evaluation of the circuits revealed small strands of fibrin on all connector rims and clots in the center part of the pump head and at the cannula tips. The lungs showed two small emboli in large size pulmonary arteries and also two minor emboli in small size arteries. In four animals the emboli were equally divided between the two groups. As expected regarding the size of the clots no influences could be seen on hemodynamic or respiratory parameters. With Scanning Electronic Microscopy a monolayer of activated thrombocytes was observed on the surface of the bypass circuits in the coated as well as in the uncoated group. This study suggests that a veno-venous bypass without systemic heparinization is possible without serious damage to blood cellular elements or impressive activation of the coagulation system.(ABSTRACT TRUNCATED AT 250 WORDS)

Inotropic effects of sodium nitroprusside: a clinical study on coronary surgery patients.

OBJECTIVE: Sodium nitroprusside (SNP) induces release of nitric oxide and is widely used as a vasoactive drug. Recent research analyzed effects of SNP on cardiac muscle and described variable inotropic effects. The present study evaluated effects of SNP on left ventricular (LV) function in patients undergoing coronary artery surgery. METHODS: The study was performed in 100 patients with a preoperative ejection fraction > 40%. LV pressures were measured with a fluid-filled catheter in the LV cavity. Hearts were placed in AV sequential mode at a rate of 90 beats/min. Measurements were obtained at end-expiration and consisted of a control tracing and a tracing obtained after a 5 min infusion of SNP 0.5 microgram.kg-1.min-1. These measurements were obtained before and after cardiopulmonary bypass (CPB). An average of 5 consecutive beats was obtained for analysis. Ventricular function was assessed with LV pressure and dP/dt. Data were analyzed using two factor analysis of variance for repeated measurements. RESULTS: 1. Baseline patient data (n = 80). Before CPB, a variable inotropic response to SNP was observed. The direction of the inotropic response was related to preoperative beta-blocking medication. LVP and dP/dtmax increased with SNP in patients without preoperative beta-blocking medication. In patients on preoperative beta-blocking medication, SNP did not alter LVP and dP/dtmax. After CPB, a positive inotropic response was not observed in any of the patients. 2. Postoperative patient data under dobutamine (n = 20). Data of these separate observations were similar to baseline data before CPB. After CPB and under dobutamine administration (5 micrograms.kg-1.min-1) all 20 patients developed a positive inotropic response to SNP. CONCLUSIONS: In coronary surgery patients, SNP induced variable inotropic effect. The direction of the inotropic response appeared to be modulated by the beta-adrenergic drive.

[Mediastinal chemodectoma (author's transl)]. / Mediastinaal chemodectoma

In 1958 a mediastinal tumor was discovered in an asymptomatic patient. She had previously complained of vomiting and an oesophageal abnormality had been discovered though not treated. The mediastinal tumor was resected and diagnosed as a non chromaffine chemodectoma. In the follow-up the mediastinal image never appeared normal and the heart shadow was enlarged. In 1974 an infiltrate appeared in the left lung. In 1975 the patient was operated : a pulmonary osteochondroma, a pericarditis and an intrapericardial aortopulmonary chemodectoma were discovered. The mediastinal chemodectoma is a rare tumor and its frequency, location and signs are discussed. The importance of angiography for diagnosis is stressed. The authors consider malignant degenerescence to be rare, and the treatment is surgical as the tumor is radioresistant. In the present case there was either a malignant recurrence or multiple focuses with a possible oesophageal location.

Chronic osteomyelitis after sternotomy.

Two patients with chronic sternal osteomyelitis after an initially uncomplicated coronary artery bypass grafting (CABG) operation are described. Chronic osteomyelitis, caused in both cases by Pseudomonas aeruginosa, occurred six and four months after CABG respectively. Because chronic infection failed to respond to local wound care and medical therapy, more radical treatment was needed. Steel wires were removed and surgical debridement was performed. In one patient, an additional omental transposition was performed. In both cases radical debridement in combination with antibiotics successfully eradicated the infection.

[Blunt and open trauma of the heart and thoracic aorta in 26 patients (author's transl)]. / Stompe en scherpe traumata van hart en thoracale aorta bij 26 patiënten.

Twenty-six patients with blunt or open trauma to the heart and thoracic aorta were admitted and 23 were operated on. Among 19 blunt trauma there were 15 ruptures of the aorta among which 12 were operated and 3 were not, 2 lesions of the ventricular septum, 1 coronary thrombosis and 1 rupture of the right atrium. In 7 open wounds there were 3 ventricular lesions; 3 cases of pericarditis and 1 aortic lesion. Among operated patients 1 died of a rupture of the aortic isthmus and another of a rupture of the aortic arch and left carotid artery. The 3 patients that were not operated died of a rupture of the aortic isthmus. In these cases the diagnosis must be set early and the aortography must be followed by an operation. In cases of an open wound early thoracotomy is recommended.