Custodiol versus Plegisol: A phase 3 multicentre myocardial protection study

BACKGROUND

While considered simple and effective, crystalloid antegrade cardioplegia solutions have had few prospective multicentre comparison trials.

METHODS

A commercial intracellular-type histidine-tryptophan-ketoglutarate (HTK) cardioplegia solution (Custodiol HTK; Köhler Chemie GmbH, Germany) designed for 4 h of protection after a single administration was compared with a standard extracellular multidose product (Plegisol [PL]; Hospira Inc, USA) in an open-label, randomized, prospective seven-institution trial. A total of 136 isolated coronary bypass patients were randomly assigned into two groups and stratified by ejection fraction into categories of 40% or greater (n=118) and 20% to 39% (n=18).

RESULTS

The mean age of the study cohort was 62 years, of which 94% were men. Seventy per cent of patients had Canadian Cardiovascular Society class III angina and 75% had three-vessel disease anatomy. Cross-clamp times were nearly identical for patients in both cardioplegia groups; however, defibrillation was needed less often for patients who were treated with HTK (64% versus 91%, P<0.01). Hospital and intensive care unit stays, creatine kinase isoenzyme MB curves, cardiac outputs, inotrope levels, and deaths or serious adverse events (PL=13, HTK=14) were very similar between groups. Logistic regression showed that myocardial infarction or possible treatment-related adverse events were associated with high cardiac troponin I (cTn-I) levels 6 h after the procedure (P=0.001), and HTK treatment (OR 3.5, P=0.01). The primary study end point (6 h post-ischemia cTn-I) favoured PL (16.7±13.2 μg/L versus 20.3±13.5 μg/L, P=0.01). Patients who underwent circumflex grafting had higher cTn-I levels with HTK (P<0.001) and 48% required reinfusions due to cardiac warming. Longer intervals between doses correlated with high cTn-I levels (P=0.02). HTK provided prolonged protection with low cTn-I release (10 μg/L or less), although this occurred less frequently than with PL (17 versus 27 patients, P=0.06).

CONCLUSIONS

HTK caused more structural protein release and adverse events than PL, even when reinfusion was implemented.

Risk-Stratified Evaluation of Amiodarone to Prevent Atrial Fibrillation After Cardiac Surgery

BACKGROUND

Amiodarone prophylaxis (AMP) reduces the prevalence of postoperative atrial fibrillation (POAF) after cardiac surgery. We investigated the impact of AMP on the frequency and duration of POAF, the intensive care unit and hospital length of stay, and its cost-effectiveness in a risk-stratified cohort.

METHODS

A retrospective, observational analysis of 509 patients who underwent cardiac surgery in 2003 was performed. Data sources included The Society of Thoracic Surgeons national database; medical and medication administration records; and the activity-based cost data from our institution. Risk stratification for POAF was determined using a validated risk index. Cost-effectiveness was determined from the hospital's perspective.

RESULTS

The mean patient age was 63 years, 27% were female, 80% underwent coronary artery bypass grafting, and 29% underwent valve surgery. When a risk-stratified evaluation was made, 50% of patients were at an elevated risk for having POAF develop. When compared with nonprophylaxed patients, those receiving AMP (59%) experienced less POAF (31% vs 22%; p = 0.027) and shorter durations of POAF (4.7 vs 2.7 days; p = 0.025). In the elevated-risk group, AMP clinically (but not significantly) reduced length of stay in the intensive care unit (101 vs 68 hours; p > 0.05) and post-procedural hospital length of stay (9.7 vs. 7.9 days, p > 0.05). In the elevated-risk group, AMP was robustly cost-effective in reducing POAF.

CONCLUSIONS

Amiodarone prophylaxis reduced the prevalence and duration of POAF. Baseline risk for POAF was a major determinant of the overall cost-effectiveness of AMP. The greatest cost savings with AMP was seen in patients at an elevated risk for POAF. These findings suggest the need for risk stratification when prescribing AMP.

Chordae Tendinae Tumor as the Cause of Cardioembolic Stroke

We describe the case of a chordae tendinae papillary fibroelastoma with patent foramen ovale and interatrial septal aneurysm in a healthy young woman who suffered from acute ischemic right middle cerebral artery infarction.

Hemolytic anemia produced by regurgitation through transposed chordae tendineae

Hemolytic anemia after mitral repair and annuloplasty ring placement is very uncommon, and rarely described. The case is presented of a 53-year-old woman who developed severe mitral regurgitation and transfusion-dependent hemolytic anemia following mitral valve repair with a Carpentier-Edwards annuloplasty ring, which included transposition of chordae tendineae from the posterior leaflet to the anterior leaflet. Transesophageal echocardiography suggested that the transposed chordae tethered the anterior leaflet, causing malcoaptation of the leaflets. This resulted in central regurgitation divided by the chordae tendineae, producing two turbulent flow jets causing hemolysis. At reoperation, these chordae were removed and two longer Gortex neochordae to the anterior leaflet were placed with subsequent resolution of the anemia. To the authors' knowledge, this is the first case of hemolytic anemia caused by transposed mitral valve chordae tendineae from the posterior to the anterior leaflet.

Tricuspid annuloplasty significantly reduces early tricuspid regurgitation after biatrial heart transplantation

BACKGROUND

The incidence of tricuspid annuloplasty (TR) observed early after cardiac biatrial implantation is unpredictable and in our experience not infrequently problematic. Although the bicaval method of implant may reduce the incidence of TR, its benefit has not been conclusively documented.

METHODS

In an attempt to reduce the incidence of TR observed early after cardiac transplantation, 25 consecutive patients undergoing cardiac transplantation received donor heart tricuspid annuloplasty (TA) with either a DeVega or Ring technique. Early transthoracic echocardiograms were analyzed and compared with an immediately prior and consecutive cohort of 25 patients undergoing transplantation without TA. The biatrial technique of cardiac transplantation with a Cabrol modification was used for donor heart implant in both groups. Echocardiograms obtained 5 days after cardiac transplantation were reviewed in blinded fashion. TR was scored 0 = none, 1 = mild, 2 = moderate, and 3 = severe.

RESULTS

Donor and recipient characteristics were not different between groups. No hospital deaths occurred in either group. Patients undergoing transplantation without TA had a higher TR score, 1.3 (range 0-3), than did patients with TA, 0.7 (range 0-1.5, p = 0.002). Moderate or severe TR was present in 8 of 25 patients without TA compared with 0 of 25 patients with TA (p = 0.004). No patients required permanent pacemaker.

CONCLUSIONS

TA can significantly reduce the incidence of early postoperative TR after biatrial cardiac transplant without adding to the complexity of operation.

Isolated left anterior descending coronary artery disease: percutaneous transluminal coronary angioplasty versus stenting versus left internal mammary artery bypass grafting

BACKGROUND

Single-vessel coronary artery disease is usually treated with PTCA; however, this approach when applied to the left anterior descending coronary artery (LAD) is hampered by high restenosis rates, often approaching 50%. Coronary stenting (STENT) and left internal mammary artery bypass grafting of the LAD (LIMA-LAD) are other options that have been successfully used for single-vessel LAD disease. The optimal mode of revascularization for patients with isolated single-vessel LAD disease is unclear. The purpose of the present study was to examine PTCA versus STENT versus LIMA-LAD with respect to short- and intermediate-term outcomes.

METHODS AND RESULTS

This was an observational retrospective cohort study comparing in-hospital and intermediate-term outcomes and functional class among patients with isolated single-vessel LAD disease revascularization. Consecutive eligible patients were grouped according to their initial revascularization procedure and systematically followed up. A total of 704 patients qualified for the study: 469 in the PTCA group, 137 in the STENT group, and 98 in the LIMA-LAD group. Follow-up data were complete for 97% of patients and averaged 27+/-13 months. In-hospital mortality for the PTCA, STENT, and LIMA-LAD groups was 1.1%, 0%, and 0% (P=0.51), respectively. Median hospital stays after the procedure for the respective treatment groups were 1, 1, and 5 days (P<0.001), and occurrences of in-hospital myocardial infarction were 0.9%, 1.5%, and 1.0% (P=NS). Repeat revascularization procedures were performed in 30%, 24%, and 5% of the PTCA, STENT, and LIMA-LAD groups (P=<0. 001 for LIMA-LAD versus other groups, P=0.11 for PTCA versus STENT). Actuarial 2-year mortality was 3.9%, 2.6%, and 1% in the PTCA, STENT, and LIMA-LAD groups (P=0.33).

CONCLUSIONS

Revascularization for isolated LAD disease using PTCA, STENT, or LIMA-LAD results in low in-hospital adverse event rates and good long-term results. Repeat procedures are required less often after LIMA-LAD than after either PTCA or STENT. Long-term mortality was not statistically different, but the trend was for the lowest mortality with LIMA-LAD, a somewhat higher mortality with STENT, and the highest mortality with PTCA.

Current trends in peripheral vascular surgery. When is surgical intervention the best option?

Surgery continues to play an important role in the management of peripheral vascular disease. Revascularization procedures provide excellent outcomes for many patients at risk for loss of a limb or seriously impaired quality of life. Although endovascular techniques are now being used for managing many vascular problems, the traditional surgical approaches still offer well-documented benefits.

Is routine postaneurysmectomy hemodynamic assessment of the inferior mesenteric artery circulation helpful?

All patients with an abdominal aortic aneurysm treated during a 27-year period by one surgical group at the MidAmerica Heart Institute were included in this study. A prospective routine postaneurysmectomy hemodynamic assessment of the inferior mesenteric artery (IMA) circulation was performed in a test group of consecutive patients operated on by one surgeon. When a mean IMA stump pressure </= approximately 50 mmHg was found, the IMA was reimplanted. Postoperatively, patients were monitored for clinical evidences of ischemic colitis. The occurrence of ischemic colonic injury was documented by colonoscopy, laparotomy, or autopsy. The incidences of ischemic colitis in the test group, a historical control group, and a concomitant control group were determined and compared. Routine hemodynamic assessment of the postaneurysmectomy IMA circulation did not favorably affect the outcome with regard to the occurrence of clinically evident ischemic colitis.

An analysis of the effect of age on survival after heart transplant

BACKGROUND

Advances in immunosuppression and reports of improved survival after cardiac transplantation have led to a liberalization of traditional recipient eligibility criteria, especially age. While age alone is not a contraindication to transplantation, conflicting data exists regarding long-term survival of the older transplant recipient.

METHODS

One hundred-fifty three patients undergoing consecutive first time cardiac transplantation from June 7, 1985 through February 1, 1997 were studied. For purposes of analysis, patients were stratified according to age (<55 years vs. >55 years) and hospital and late outcomes determined.

RESULTS

The incidence of early and late acute cellular rejection was not different based up on age. The freedom from infection at 12 months was 54+/-5% for patients < or =55 compared to 32+/-8% for patients >55 years old (p = .04). Five year estimated survival for patients >55 years old was only 56+/-9% compared to 78+/-5% for patients < or =55 years old (p = .005). The hazard for death was highest within the first post-transplant year for older patients and was most commonly due to infection. Both advanced age and pre-transplant diagnosis of ischemic cardiomyopathy were found to be independently and additively predictive of reduced late survival.

CONCLUSIONS

In the present study, late survival was adversely influenced by advanced age. Older patients (>55 years) with pre-transplant diagnosis of ischemic cardiomyopathy were particularly at high risk (risk ratio 4.6:1) for death. Given little prospect of expanding the number of donor hearts, careful selection of patients over the age of 55 with pre-transplant ischemic cardiomyopathy is warranted.

25-year trends in resection of abdominal aortic aneurysms

An attempt was made to document trends that have occured over a 25-year period in clinical presentation, preoperative evaluation, operative management, and patient outcome in patients with an abdominal aortic aneurysm. The experience (574 aneurysmectomies) of one cardiovascular surgical group was analyzed by retrospective review of hospital and office records. Changes over time of patients' ages, aneurysm sizes and statuses, prior myocardial revascularization, operative mortality, and certain other parameters were evaluated. During the period of study, there was a significant decrease in aneurysm size, increase in patients' ages, and an increased incidence of previous coronary artery bypass. No ruptured aneurysm was < 5 cm in diameter. The incidence of rupture and the operative mortality in patients with a ruptured aneurysm did not change significantly. There was a significantly (p = 0.03) lower operative mortality of 0.4% in the latter half of the series for elective aneurysmectomy. Increased utilization of preoperative cardiologic evaluation, and myocardial revascularization, has been associated with a decreased operative mortality in patients undergoing elective aneurysmectomy even though the patients are now older and have more age-related comorbidities. Elective aneurysmectomy should be offered to most patients when an abdominal aortic aneurysm is > or =5 cm in diameter.

Coronary artery bypass for isolated disease of the left anterior descending artery. Late survival of 648 patients

We studied a series of 648 consecutive patients who underwent coronary artery bypass grafting for isolated primary disease of the anterior descending coronary artery. We evaluated the patients periodically during a long-term follow-up period of up to 17 years. We studied factors such as survival, survival without acute event (i.e., acute myocardial infarction, repeat coronary artery bypass, and percutaneous transluminal coronary angioplasty), and asymptomatic survival (i.e., survival without acute event or angina). We further analyzed these factors as they occurred in patients who received only saphenous vein grafts versus their occurrence in patients who received internal mammary artery grafts. There was 1 death in the early postoperative period (defined as 30 days or earlier after the operation). The 5-, 10-, and 15-year survival rates were 94.8%, 86.6%, and 72.2%, respectively. These survival rates are slightly better than those of an age- and sex-matched United States census population. In our series, the rates of survival, event-free survival, and asymptomatic survival were better, although not significantly so, in the group of 108 patients in whom the internal mammary artery was used as the bypass conduit. We conclude that patients who undergo coronary artery bypass grafting for isolated disease of the left anterior descending coronary artery enjoy normal survival rates, in comparison with the survival rates of an age- and sex-matched United States census population, through at least the 1st 16 postoperative years. Additionally, patients who receive an internal mammary artery bypass graft have slightly better rates of survival, event-free survival, and asymptomatic survival than do those who receive only saphenous vein grafts.

Early repair of postinfarction ventricular septal rupture

BACKGROUND

Postinfarction rupture of the interventricular septum is usually fatal without surgical intervention. The optimal timing and the most appropriate technique of surgical repair remain unsettled.

METHODS

The results of surgical closure of postinfarction ventricular septal defect in a consecutive series of patients seen over a 24-year period were reviewed and analyzed. Late follow-up was obtained in all patients who survived the operation.

RESULTS

Sixty of 76 patients treated surgically exhibited cardiogenic shock, low cardiac output syndrome, or both at the time of operation. A plan of early operative intervention was followed in these unstable patients, with 60% of them undergoing repair within 24 hours of septal rupture. For the entire series of patients, the hospital mortality rate was 40.8%; survival was 41.5% at 5 years and 25.6% at 10 years postoperatively.

CONCLUSIONS

Significant trends observed during the period of study were a more aggressive stance regarding surgical intervention in all patients who presented with hemodynamic instability and improved survival in those patients who presented with septal rupture complicating an inferior myocardial infarction.

Right atrial compression related to defibrillator patches

Acceptable function of an internal defibrillator can be achieved with different patch orientations. For patients requiring defibrillator patches concomitant with a cardiac procedure requiring extracorporeal circulation, application of one of the patches within the pericardium adjacent to the right atrium has provided excellent defibrillation thresholds. We describe 4 such patients in whom a compressing thrombus subsequently developed between the patch and the atrium. The thrombus was small and asymptomatic in 1 patient, but caused localized tamponade requiring reexploration in 2 patients and a fatal superior vena caval obstruction in 1. The precise etiology of this serious complication remains unclear, but its occurrence argues against the application of intrapericardial defibrillator patches in this orientation.

Mitral valve repair using a flexible and adjustable annuloplasty ring

Initial experience with a new flexible and adjustable mitral annuloplasty ring is described. Used in conjunction with standard techniques of mitral valve repair, this ring was implanted in 21 consecutive patients undergoing elective operation for mitral regurgitation. Satisfactory valve repair was feasible in 20 of these patients. Once the ring was sewn in place, adjustment of the ring to reduce or eliminate residual regurgitation was beneficial in 9 patients. Excellent results were achieved as determined by intraoperative transesophageal echocardiography. Comparable late results were found in all but 1 patient up to 1 year after repair. This patient required mitral valve replacement 6 months after repair due to failure of papillary muscle reconstruction. The BiFlex ring has the merits of a flexible prosthesis with the advantage of easy adjustment once secured in place.

Surgical closure of the patent ductus arteriosus in the neonatal intensive care unit

Efficacy of surgical closure versus indomethacin for treatment of patent ductus arteriosus in symptomatic neonates is an ongoing controversy. In recent years, surgical closure has been performed in the neonatal intensive care unit rather than the operating room in some centers, creating further controversy. In a retrospective study of the charts of 115 sequential patent ductus arteriosus surgical closures performed in the neonatal intensive care unit in premature infants, we found no surgical morbidity or mortality. Ninety-nine of these infants of less than 33 weeks gestational age were evaluated for various factors that might influence outcome. All were operated on within 72 hours of diagnosis, with an extra-pleural approach and metal clips used for closure of the ductus. All infants were extubated at an average of 33 weeks in each age group studied unless they had underlying severe bronchopulmonary dysplasia. We conclude that surgical closure of the symptomatic patent ductus arteriosus in neonates is safe and 100% effective, with none of the reported complications of indomethacin therapy, and should be the treatment of choice in neonates aged less than 33 weeks (gestational age) at birth with symptomatic patent ductus arteriosus. Closure performed in the neonatal intensive care unit eliminates transport risks and is ultimately safer and easier than transport to an operating room.

Mitral valve fibroelastoma

Papillary fibroelastomas are rare benign tumors of the heart with predisposition for cardiac valvular involvement that were traditionally incidental findings at autopsy. Echocardiography now is allowing clinicians to diagnose these tumors in living patients. We reviewed the literature and, to our knowledge, are reporting the fifth documented case of a mitral valve papillary fibroelastoma in a living patient. Our patient was seen with bilateral transient ischemic attacks and was found to have a mitral valve tumor by two-dimensional echocardiography and cardiac catheterization. The tumor involved the entire mitral valve and subvalvular structures. The patient's valve was replaced with a bioprosthesis, and she remains free from symptoms.