Robert L. Hannan

Cardiac Operations in Patients Aged 70 Years and Over: Mortality, Length of Stay, and Hospital Charge

BACKGROUND With emphasis today on cost containment in health care, the results and costs of cardiac operations in elderly patients are being scrutinized. METHODS Our computerized database was used to obtain the characteristics of patients undergoing cardiac operations from January 1990 to July 1994. A study group of 628 patients aged 70 years and over was identified, and comparisons were made between them and adult patients less than 70 years of age. RESULTS In the elderly group the 30-day mortality was 33 of 628 (5.3%), and the overall hospital mortality was 40 (6.4%). During this time the 30-day mortality for all adult patients less than 70 years old was 49 of 1787 (2.7%; p < 0.003) and the hospital mortality was 59 (3.3%; p < 0.001). The mean length of postoperative hospital stay (days +/- standard error) in all surviving patients aged 70 years and over was 11.6 +/- 0.4 days, compared with 8.5 +/- 0.2 days in patients less than 70 years old (p < 0.001). Over the time of the study the length of stay in patients less than 70 years old declined from 9.6 +/- 0.4 to 7.2 +/- 0.6 days, whereas it stayed the same for elderly patients. The 30-day mortality and length of stay increased with the risk category of the Parsonnet model. The mean hospital charge for patients aged 70 and over was 114% of that for younger patients. CONCLUSIONS Although mortality, length of stay, and hospital charge are increased in patients 70 years of age and over, they are not excessively so. The results support the continued performance of cardiac surgical procedures in select elderly patients.

The combination of propranolol and magnesium does not prevent postoperative atrial fibrillation

BACKGROUND Atrial fibrillation is a common complication of cardiovascular surgery. Beta-blockers have been shown to decrease the incidence of postoperative atrial fibrillation. However, the use of magnesium is more controversial. It was our hypothesis that adjunctive magnesium sulfate would improve the efficacy of beta-blockers alone in the prevention of postoperative atrial fibrillation. METHODS We prospectively randomized 167 coronary artery bypass patients (mean age 61+/-10 years, 115 men) to receive propranolol alone (20 mg four times daily) or propranolol and magnesium (18 g over 24 hours). Magnesium was begun intraoperatively, and propranolol was started on admission to the intensive care unit. RESULTS Using an intention-to-treat analysis, the incidence of postoperative atrial fibrillation was 19.5% in the propranolol-treated patients and 22.4% in propranolol + magnesium-treated patients (p = 0.65). Because combination therapy resulted in an excess of postoperative hypotension, which required withholding doses of propranolol, an on-treatment analysis was also performed. In this analysis, the incidence of atrial fibrillation was still not significantly different (18.5% in propranolol-treated patients and 10.0% in propranolol + magnesium-treated patients, p = 0.20). CONCLUSIONS Adjunctive magnesium sulfate, in combination with propranolol, does not decrease the incidence of postoperative atrial fibrillation.

Nonanticoagulant Heparin Prevents Coronary Endothelial Dysfunction After Brief Ischemia-Reperfusion Injury in the Dog

BACKGROUND Coronary endothelial dysfunction after brief ischemia-reperfusion (IR) remains a clinical problem. We investigated the role of heparin and N-acetylheparin, a nonanticoagulant heparin derivative, in modulating coronary endothelial function after IR injury, with an emphasis on defining the role of the nitric oxide (NO)-cGMP pathway in the heparin-mediated effect. METHODS AND RESULTS Male mongrel dogs were surgically instrumented, and the effects of both bovine heparin and N-acetylheparin on coronary endothelial vasomotor function, expressed as percent change from baseline flow after acetylcholine challenge, were studied after 15 minutes of regional ischemia of the left anterior descending artery (LAD) followed by 120 minutes of reperfusion. In dogs treated with placebo (saline), coronary vasomotor function was significantly (P</=0.03) decreased after 15 and 30 minutes of reperfusion (65+/-12% and 73+/-12%) compared with preischemia (103+/-6%). In contrast, the vasodilatory response to the endothelium-independent vasodilator sodium nitroprusside was maintained during reperfusion. Preischemic administration of both bovine heparin and N-acetylheparin (6.0 mg/kg IV) preserved coronary endothelial function throughout reperfusion. In a parallel group of dogs, nitrate/nitrite (NOx) and cGMP levels in the LAD were measured after treatment and during 15-minute reperfusion. Preischemic administration of N-acetylheparin caused a significant increase in basal NOx and cGMP levels compared with saline controls. Pretreatment with N-acetylheparin also caused a significant increase in NOx and cGMP levels in the LAD after 15 minutes of reperfusion compared with IR alone. CONCLUSIONS These results suggest that heparin preserves coronary endothelial function after brief IR injury by a mechanism independent of its anticoagulant activity and that the effect of heparin may be mediated in part by activation of the NO-cGMP pathway.

The successful use of alternative routes of vascular access for performing pediatric interventional cardiac catheterization.

Objective: The objective of this study is to examine the safety/efficacy of alternative routes of vascular access (ARVA) for successful performance of interventions. Background: Complex interventional catheterizations may be required in children with limited vascular access, vascular constraints relative to size, and hemodynamic instability. Our approach has been to utilize ARVA in selected cases. Methods: ARVA pertains to any vessel excluding femoral, jugular/subclavian veins, or umbilical access. A retrospective review performed on patients with an intervention utilizing ARVA between August 1995 and January 2004 was performed. Patients were divided by clinical status: critically ill/emergent (A), elective cases (B). Procedural success was based on previously published criteria. Results: Sixty‐four interventions were performed in 50 patients using 54 ARVA. ARVA utilized: radial (1), axillary (2), brachial (2), carotid arteries (25); brachial (2) hepatic (9) veins; and open chest/direct cardiac puncture (13). ARVA provided successful access to target lesions. Interventions included stents (30), valvuloplasty (16), angioplasty (14), and one each of vascular occlusion, septal occlusion, accessory pathway ablation, and septostomy. Group A patients were smaller (P < 0.0002) and younger (P < 0.004) than B. All open chest/direct cardiac and the majority (71%) of carotid arterial approaches were performed in group A. Fifty‐six (88%) inteventions were successful with no difference between groups A (88%) and B (86%). There were two complications. Neither resulted in long‐term sequelae. Conclusions: ARVA may provide a strategic advantage that may be safely applied to a variety of interventions regardless of patient size or degree of illness. These techniques may further extend the scope of successful interventions in children.

Transforming patient and family access to medical information: utilisation patterns of a patient-accessible electronic health record.

OBJECTIVE The purpose of this study was to evaluate the utilisation of a web-based multimedia patient-accessible electronic health record, for patients with congenital cardiac disease. PATIENTS AND METHODS This was a prospective analysis of patients undergoing congenital cardiac surgery at a single institution from 1 September, 2006 to 1 February, 2009. After meetings with hospital administration, physicians, nurses, and patients, we configured a subset of the cardiac programs web-based clinical electronic health record for patient and family access. The Electronic Health Record continuously measured frequency and time of logins, logins during and between hospitalisations, and page views by type (imaging versus textual data). RESULTS Of the first 270 patients offered access to the system, 252 became users (93% adoption rate). System uptime was 99.9%, and no security breaches were reported. Users accessed the system more often while the patients were in hospital (67% of total logins) than after discharge (33% of total logins). The maximum number of logins by a family was 440, and the minimum was 1. The average number of logins per family was 25. Imaging data were viewed significantly more frequently than textual data (p 0.001). A total of 12 patients died during the study period and 11 members of their families continued to access their Electronic Health Records after the date of death. CONCLUSIONS A web-based Patient Accessible Electronic Health Record was designed for patients with congenital cardiac disease. The adoption rate was high, and utilisation patterns suggest that the Electronic Health Record could become a useful tool for health information exchange.

Assisted venous drainage cardiopulmonary bypass in congenital heart surgery.

BACKGROUND A novel active venous drainage perfusion circuit was designed to achieve effective venous return through small venous cannulas. The efficacy and safety of this new system was investigated and compared with a conventional gravity drainage system. METHODS Four hundred consecutive patients undergoing open heart repair of congenital heart lesions by one surgeon were studied. The first 200 patients were supported by gravity drainage and the next 200 patients were supported by assisted venous drainage. No patient in the time period was excluded from the study. RESULTS The two groups did not differ significantly in weight, bypass time, or cross-clamp time. Priming volumes were less in the assisted group than in the gravity group (576+/-232 mL versus 693+/-221 mL, p < 0.001). Venous cannula size was smaller in the assisted group when compared with the gravity group (33.2F+/-7.4F versus 38.5F+/-7.1F, p < 0.001). There was a trend to lower operative mortality in the assisted drainage group (5 of 200, 2.5% versus 11 of 200, 5.5%; p = 0.10). Hospital stay and pulmonary, infectious, and neurologic complications were comparable in both groups. Cardiac complications were less common in the assisted group than in gravity group (22 of 200, 11% versus 38 of 200, 19%; p = 0.017). Hematologic complications were less common in the assisted group than the gravity group (6 of 200, 3% versus 19 of 200, 9.5%; p < 0.01). CONCLUSIONS These findings suggest that assisted venous drainage is safe in congenital heart operations and facilitates the use of smaller venous cannulas.

Endovascular stent graft treatment of a pulmonary artery pseudoaneurysm.

A 5-year-old girl with pulmonary atresia, ventricular septal defect, hypoplastic pulmonary arteries, and multiple pulmonary artery reconstructive procedures presented with an enlarging pulmonary artery pseudoaneurysm. A previous attempt to occlude the aneurysm was unsuccessful and the aneurysm continued to enlarge. We describe the percutaneous placement of an endovascular stent graft to occlude the aneurysm. This novel use of a covered graft effectively treated a potentially lethal problem without reoperative thoracotomy or sternotomy.

Heparin And Nonanticoagulant Heparin Preserve Regional Myocardial Contractility After Ischemia-Reperfusion Injury: Role Of Nitric Oxide

OBJECTIVES These studies were performed to determine the effect of heparin and nonanticoagulant heparin on myocardial function after ischemia-reperfusion and to further evaluate the role that the nitric oxide-cyclic guanosine monophosphate pathway plays in mediating the effect of heparin. METHODS Fifteen dogs were subjected to 15 minutes ischemia followed by 120 minutes reperfusion and pretreated with either saline solution, bovine heparin (6.0 mg/kg intravenously), or N-acetyl heparin (6.0 mg/kg intravenously), a heparin derivative without anticoagulant properties. The left anterior descending artery was occluded for 15 minutes and regional systolic shortening, a unitless measure of myocardial contractility, assessed during reperfusion. To evaluate the role of nitric oxide, the inhibitor N(omega)-nitro-L-arginine, 1.5 mg/kg intracoronary, was given before heparin administration. Myocardial levels of cyclic guanosine monophosphate, the second messenger of nitric oxide, were also measured in the N-acetyl heparin group using radioimmunoassay. RESULTS Regional systolic shortening was significantly decreased in the saline group during 60 and 120 minutes compared with before ischemia (9.2 +/- 1.0 and 9.0 +/- 0.9 vs 12.2 +/- 1.2, p < or = 0.0003). Heparin and N-acetyl heparin-treated dogs, however, showed preservation of systolic shortening throughout reperfusion. Administration of nitro-L-arginine significantly attenuated the protective effect of heparin (9.2 +/- 1.2 vs 12.7 +/- 1.1, p < or = 0.0001) and N-acetyl heparin (9.3 +/- 0.3 vs 12.8 +/- 0.4, p < or = 0.0001) during 120 minutes reperfusion. Myocardial levels of cyclic guanosine monophosphate were also significantly increased in the N-acetyl heparin group compared with saline (199.1 +/- 7.1 vs 103.5 +/- 4.5 pmol/mg, p < or = 0.0001). CONCLUSIONS Heparin preserves myocardial contractility after ischemia-reperfusion independent of its anticoagulant properties. Furthermore, the protective effects of heparin during ischemia-reperfusion are mediated, at least in part, through a nitric oxide-cyclic guanosine monophosphate pathway.

Video-assisted cardioscopy for intraventricular repair in congenital heart disease.

BACKGROUND Video-assisted thoracoscopic surgical techniques have been widely adopted as a means to reduce surgical trauma. By adapting pediatric thoracoscopic instrumentation, we have developed a technique for video-assisted cardioscopy (VAC). We report our experience and describe the technical feasibility of VAC. METHODS Since June 1995, 409 consecutive patients underwent 431 intracardiac procedures (ventricular septal defect, 150; tetralogy of Fallot or double outlet right ventricle, 101; atrioventricular canal, 52; subaortic stenosis, 43; valve repair, 50; Rastelli procedure, 12; Konno or Ross Konno operation, 11; and miscellaneous, 12) using VAC at Miami Childrens Hospital. Using a prospective database, we tracked outcomes and operative events to delineate the usefulness and efficacy of this technique. RESULTS VAC provided clear and precise imaging of small or remote intracardiac structures during repair of congenital heart defects without technical complications. Procedure times and aortic cross-clamp times using VAC were not prolonged. Intraoperative images were collected for every operation, documenting each patients cardiac anatomy before and after repair. Surgery through small incisions was facilitated. Operative mortality was 1.2% (5 of 409), and no patient required reoperation before discharge. At a mean follow-up interval of 22 months, the incidence of reoperation for residual or recurrent lesions was 1.2% (5 of 404). CONCLUSIONS Our experience demonstrates the technical feasibility and clinical utility of routine endoscopic imaging during open heart surgery for congenital heart repair.

Heparin preserves nitric oxide activity in coronary endothelium during ischemia-reperfusion injury

BACKGROUND Brief episodes of ischemia followed by reperfusion adversely affect endothelial vasomotor function. We hypothesized that heparin may impart a protective effect on the coronary endothelium during ischemia-reperfusion injury possibly via the nitric oxide pathway. METHODS Eighteen anesthetized dogs were randomly assigned to one of two treatment groups: saline solution or bovine heparin (6.0 mg x kg intravenously). A flow probe and cannula were placed in the left anterior descending artery. Functional recovery of the coronary endothelium was assessed after 15 minutes of ischemia and during 120 minutes of reperfusion after acetylcholine and nitroprusside challenge. In a separate group (n = 10), nitric oxide activity was measured as nitrate/nitrite levels and cyclic guanosine monophosphate levels in the left anterior descending artery. RESULTS Control dogs displayed a significant decrease in percent change of left anterior descending artery flow at 15, 30, and 60 minutes of reperfusion (67%+/-8%, 76% +/-11%, and 84%+/-8%) when compared with preischemic values (108+/-6; p < 0.01). Heparinized dogs, however, showed preservation of coronary endothelial function after acetylcholine challenge throughout reperfusion. Heparin-treated dogs also displayed a significant increase in nitrate/nitrite levels during reperfusion (37.3+/-4.1 micromol/L) when compared with the saline group (24.3+/-0.8 micromol/L; p < 0.03). Left anterior descending artery levels of cyclic guanosine monophosphate were also significantly increased after heparin administration (3.0+/-0.3 pmol/mg) when compared with ischemia-reperfusion alone (0.7+/-0.1 pmol/mg; p < 0.03). CONCLUSIONS Heparin preserves the vasoregulatory function of the coronary endothelium during brief episodes of ischemia-reperfusion injury, in part, via the nitric oxide pathway. Administration of heparin may have important therapeutic implications in the prevention of coronary endothelial dysfunction associated with reperfusion injury.