Paul W. Weldner

Comparing long-term survival of patients with multivessel coronary disease after CABG or PCI: Analysis of BARI-like patients in Northern New England

Background—Randomized trials comparing coronary artery bypass graft surgery (CABG) with percutaneous coronary interventions (PCIs) for patients with multivessel coronary disease (MVD) report similar long-term survival for CABG and PCI. These studies used a highly selected population of patients and providers, and their results may not be generalizable to actual care. Our goal in this study was to compare long-term survival of MVD patients treated with CABG vs PCI in contemporary practice. Methods and Results—From our northern New England registries of consecutive coronary revascularizations, we identified 10 198 CABG and 4295 PCI patients with MVD who may have been eligible for either procedure between 1994 and 2001. Vital status was obtained by linkage to the National Death Index. Proportional-hazards regression was used to calculate hazard ratios (HRs) for survival in CABG vs PCI patients after adjustment for comorbidities and disease characteristics. CABG patients were older; had more comorbidities, more 3-vessel disease, and lower ejection fractions; and were more completely revascularized. Adjusted long-term survival for patients with 3-vessel disease was better after CABG than PCI (HR, 0.60; P<0.01) but not for patients with 2-vessel disease (HR, 0.98; P=0.77). The survival advantage of CABG for 3-vessel disease patients was present in all patient populations, including women, diabetics, and the elderly and in the era of high stent utilization. Conclusions—In contemporary practice, survival for patients with 3-vessel coronary disease is better after CABG than PCI, an observation that patients and physicians should carefully consider when deciding on a revascularization strategy.

The Norwood operation and subsequent Fontan operation in infants with complex congenital heart disease

From April 1987 to September 1993, 60 infants underwent a Norwood operation for complex congenital heart disease including hypoplastic left heart syndrome (n = 41), ventricular septal defect and subaortic stenosis with aortic arch interruption/severe coarctation (n = 7), complex single right ventricle with subaortic stenosis (n = 8), critical aortic stenosis with endocardial fibroelastosis (n = 2), and malaligned primum atrial septal defect with coarctation (n = 2). Age at operation ranged from 1 day to 3.9 months (mean 9 days, median 3.5 days). The operative mortality (< 30 days) was 33% (20 patients). Late mortality was 17% (10 patients). Nine of the 20 (45%) operative deaths occurred during the first 2 days after the operation as a result of sudden hemodynamic instability. All four infants with premature closure of the foramen ovale had pulmonary lymphangiectasia and died of pulmonary failure. Seven operative deaths have occurred in 36 patients since 1990 (19%); in the past 2 years, no operative deaths have occurred in 22 patients. Overall, there are 30 long-term survivors (50%). Twenty-one of these 30 infants have undergone a two-stage repair with a modified Fontan operation at 7.3 to 27.6 months of age (mean 18.1 months) with no mortality. Six patients have entered a three-stage repair strategy by undergoing a hemi-Fontan procedure at 6.8 to 23.0 months (mean 8.8 months) with no mortality, and two of these patients have now had their modified Fontan operation at 23.0 to 46.7 months of age with no mortality (four are still awaiting surgery). Two patients have undergone a two-ventricle repair with a Rastelli procedure, with no mortality at 7.4 and 14.1 months of age. Early in our experience, infants undergoing the Norwood operation had a high early mortality most often related to sudden hemodynamic instability. After we instituted a protocol that adds carbon dioxide to the inspired gas during postoperative mechanical ventilation, the postoperative course became more stable and there have been no operative deaths. In summary, the operative mortality for the Norwood operation continues to improve. A subsequent Fontan operation can be performed with excellent clinical results.

Detection and Elimination of Microemboli Related to Cardiopulmonary Bypass

Background—Neurobehavioral impairment is a common complication of coronary bypass surgery. Cerebral microemboli during cardiopulmonary bypass (CPB) are a principal mechanism of cognitive injury. The aim of this work was to study the occurrence of cerebral embolism during CPB and to evaluate the effectiveness of evidence-based CPB circuit component and process changes on the exposure of the patient to emboli. Methods and Results—M-Mode Doppler was used to detect emboli in the inflow and outflow of cardiopulmonary circuit and in the right and left middle cerebral arteries. Doppler signals were merged into a single display to allow real-time associations between discrete clinical techniques and emboli detection. One hundred sixty-nine isolated coronary artery bypass grafting (CABG) patients were studied between 2002 and 2008. There was no statistical difference in median microemboli detected in the inflow of the CPB circuit, (Phase I, 931; Phase II, 1214; Phase III, 1253; Phase IV, 1125; F [3,158]=0.8, P=0.96). Significant changes occurred in median microemboli detected in the outflow of the CPB circuit across phases, (Phase I, 702; Phase II, 572; Phase III, 596; Phase IV, 85; F [3,157]=13.1, P<0.001). Significant changes also occurred in median microemboli detected in the brain across phases, (Phase I, 604; Phase II, 429; Phase III, 407; Phase IV, 138; F [3,153]=14.4, P<0.001). Changes in the cardiopulmonary bypass circuit were associated with an 87.9% (702 versus 85) reduction in median microemboli in the outflow of the CPB circuit (P<0.001), and a 77.2% (604 versus 146) reduction in microemboli in the brain (P<0.001). Conclusions—Changes in CPB techniques and circuit components, including filter size and type of pump, resulted in a reduction in more than 75% of cerebral microemboli.

Appropriateness of Coronary Artery Bypass Graft Surgery Performed in Northern New England

OBJECTIVES The goal of this study was to assess the concordance between the American College of Cardiology (ACC) and the American Heart Association (AHA) 2004 Guideline Update for Coronary Artery Bypass Graft Surgery and actual clinical practice. BACKGROUND There is substantial geographic variability in the population-based rates of coronary artery bypass graft (CABG) procedures, and in recent years, there have been several public concerns about unnecessary cardiac care. The actual rate of inappropriate cardiac procedures is unknown. METHODS We evaluated 4,684 consecutive isolated coronary artery bypass graft procedures performed in 2004 and 2005 in northern New England. Our regional registry data were used to categorize patients into clinical subgroups. Detailed clinical criteria were then used to categorize procedures within these subgroups as class I (useful and effective), class IIa (evidence favors usefulness), class IIb (evidence less well established), and class III (not useful or effective). RESULTS Among these 4,684 procedures, we were able to classify 99.6% (n = 4,665). The majority of procedures were class I (87.7%). Class II procedures totaled 10.9%. The remaining 1.4% of procedures were class III. CONCLUSIONS In this regional study, we found that 98.6% of CABG procedures that could be classified were considered to be appropriate. In these data, actual clinical practice closely follows the recommendations of the 2004 ACC/AHA guidelines for CABG surgery.

An alternative method for repair of aortico-left ventricular tunnel associated with severe aortic stenosis presenting in a newborn.

Although a rare congenital anomaly, aortico-left ventricular tunnel (ALVT) presents in infants as severe aortic regurgitation which can be successfully corrected at the time of diagnosis. In this neonatal case of ALVT, the dominant clinical presentation was of severe aortic stenosis. Ultimately, aortic root replacement with an aortic homograft was required to repair both the ALVT and the dysplastic, stenotic aortic valve.

Intra-operative quality assessment of coronary artery bypass grafts

Early coronary artery bypass graft (CABG) failure is a troubling complication that may result in a wide range of problems, including refractory angina, myocardial infarction, low cardiac output, arrhythmia, and fatal heart failure. Early graft failures are related to poor quality and size of the distal native vascular bed, coagulation abnormalities, or technical problems involving the graft conduits and anastomoses. Unfortunately, graft failure is difficult to detect during surgery by visual assessment, palpation, or conventional monitoring. We evaluated the accuracy and utility of a transit-time, ultrasonic flow measurement system for measurement of CABGs. There were no differences between transit-time measurements and volumetric-time collected samples in an in vitro circuit over a range of flows from 10 to 100 ml/min (Bland and Altman Plot, 1.96 SD). Two hundred and ninety-eight CABGs were examined in 125 patients. Graft flow rate was proportional to the target vessel diameter. Nine technical errors were detected and corrected. Flow waveform morphology provided valuable information related to the quality of the anastamosis, which led to the immediate correction of technical problems at the time of surgery.

Does Use of Bilateral Internal Mammary Artery Grafting Reduce Long-Term Risk of Repeat Coronary Revascularization?: A Multicenter Analysis

Background: Although previous studies have demonstrated that patients receiving bilateral internal mammary artery (BIMA) conduits during coronary artery bypass grafting have better long-term survival than those receiving a single internal mammary artery (SIMA), data on risk of repeat revascularization are more limited. In this analysis, we compare the timing, frequency, and type of repeat coronary revascularization among patients receiving BIMA and SIMA. Methods: We conducted a multicenter, retrospective analysis of 47 984 consecutive coronary artery bypass grafting surgeries performed from 1992 to 2014 among 7 medical centers reporting to a prospectively maintained clinical registry. Among the study population, 1482 coronary artery bypass grafting surgeries with BIMA were identified, and 1297 patients receiving BIMA were propensity-matched to 1297 patients receiving SIMA. The primary end point was freedom from repeat coronary revascularization. Results: The median duration of follow-up was 13.2 (IQR, 7.4–17.7) years. Patients were well matched by age, body mass index, major comorbidities, and cardiac function. There was a higher freedom from repeat revascularization among patients receiving BIMA than among patients receiving SIMA (hazard ratio [HR], 0.78 [95% CI, 0.65–0.94]; P=0.009). Among the matched cohort, 19.4% (n=252) of patients receiving SIMA underwent repeat revascularization, whereas this frequency was 15.1% (n=196) among patients receiving BIMA (P=0.004). The majority of repeat revascularization procedures were percutaneous coronary interventions (94.2%), and this did not differ between groups (P=0.274). Groups also did not differ in the ratio of native versus graft vessel percutaneous coronary intervention (P=0.899), or regarding percutaneous coronary intervention target vessels; the most common targets in both groups were the right coronary (P=0.133) and circumflex arteries (P=0.093). In comparison with SIMA, BIMA grafting was associated with a reduction in all-cause mortality at 12 years of follow-up (HR, 0.79 [95% CI, 0.69–0.91]; P=0.001), and there was no difference in in-hospital morbidity. Conclusions: BIMA grafting was associated with a reduced risk of repeat revascularization and an improvement in long-term survival and should be considered more frequently during coronary artery bypass grafting.

Accessory mitral valve associated with coarctation of the aorta and bicuspid aortic valve without left ventricular outflow tract obstruction.

i p s t b ACCESSORY MITRAL VALVE (AMV) is a rare congenital cardiac anomaly that most frequently presents as heart failure secondary to left ventricular outflow tract (LVOT) obstruction. AMV is diagnosed most commonly in youth; however, much less frequently, it may present in the older population. It almost always occurs in concert with other congenital cardiac anomalies. An uncommon presentation of AMV without LVOT obstruction in an elderly patient with a history of aortic coarctation and congenital biscuspid aortic valve is described.

Early Degeneration of a Bioprosthetic Mitral Valve Complicated by a Large Left Atrial Thrombus

The authors report the case of a patient with symptomatic early bioprosthetic mitral valve deterioration in the setting of calcium supplementation. This was further complicated by a large left atrial thrombus despite supratherapeutic anticoagulation and a previously oversewn left atrial appendage. As mechanical valves are less predisposed to calcification in comparison with bioprosthetic implants, the patient underwent a mechanical mitral valve replacement in addition to a left atrial thrombectomy.

Analysis of edge-tracking errors inherent in fluoroscopic images of the beating heart.

RATIONALE AND OBJECTIVES.Because of the complex relationships between the dynamic three-dimensional cardiac surface shape and its projected image, errors arise with the use of two-dimensional silhouettes to measure displacements of the heart. The character and frequency of such errors are examined. METHODS.A high-precision x-ray scatter imaging technique was used to reconstruct the three-dimensional shape of the left ventricular free wall throughout the cardiac cycle. Displacements of the three-dimensional surface were then compared with those on the two-dimensional projected silhouette. Silhouette displacement errors were determined as a function of time during the cardiac cycle and variability between hearts. RESULTS.Differences between silhouette measurements and those on the cardiac surface range from 0% to 125% of peakto- peak displacements occur, along 33% to 75% of the silhouette contours and cover 66% of the cardiac cycle. CONCLUSION.Two-dimensional silhouette displacements provide inconsistent measurements of motion patterns on the three-dimensional cardiac surface.