Metadata and computer-based patient records.

"Metadata" is the fundamental set of items in the organization of health-care information, at least in computer-based patient records. Computer-based patient records remain controversial, and thus, to a considerable extent, the truth of all assertions about these areas remains a matter of opinion. A set of opinions generated during 5 years of exclusive and intense work is presented.

Peroxynitrite irreversibly decreases diastolic and systolic function in cardiac muscle.

Much of the damaging action of nitric oxide in heart may be due to its diffusion-limited reaction with superoxide to form peroxynitrite. Direct infusion of peroxynitrite into isolated perfused hearts fails to model the effects of in situ formation because the bulk of peroxynitrite decomposes before reaching the myocytes. To examine the direct effects of peroxynitrite on the contractile apparatus of the heart, we exposed intact and skinned rat papillary muscles to a steady state concentration of 4-microM peroxynitrite for 5 min, followed by a 30-min recovery period to monitor irreversible effects. In intact muscles developed force fell immediately to 26% of initial force, recovering to 43% by 30 min. Resting tension increased by 600% immediately, and was still elevated 500% by 30 min. Nitrotyrosine immunochemistry showed that peroxynitrite can induce tyrosine nitration at low concentrations and is capable of penetrating 200-380 microm into the papillary muscle after a 5-min infusion. Decomposed peroxynitrite had no effect on either intact or skinned muscle developed force or resting tension. Our results show that peroxynitrite directly damages both developed force and resting tension of isolated heart muscle, which can be extrapolated to systolic and diastolic injury in intact hearts.

Influence of study goals on study design and execution.

From the viewpoint of a clinician who makes recommendations to patients about choosing from the multiple possible management schemes, quantitative information derived from statistical analyses of observational studies is useful. Although random assignment of therapy is optimal, appropriately performed studies in which therapy has been nonrandomly "assigned" are considered acceptable, albeit occasionally with limitations in inferences. The analyses are considered most useful when they generate multivariable equations suitable for predicting time-related outcomes in individual patients. Graphic presentations improve communication with patients and facilitate truly informed consent.

Outflow obstruction after the arterial switch operation: a multiinstitutional study. Congenital Heart Surgeons Society.

OBJECTIVE: Our objectives were to discover whether outflow obstruction immutably accompanies the arterial switch operation and to identify factors that may decrease its prevalence. METHODS: Percutaneous or surgical reintervention for obstruction after an arterial switch was selected as an end point for obstruction. Its risk factors were identified by time-related multivariable analyses of yearly follow-up data from 514 neonates with simple transposition or transposition with ventricular septal defect entering 23 institutions before 15 days of age between January 1, 1985, and March 1, 1989. RESULTS: Sixty-two patients underwent 86 reinterventions for right-sided obstruction (83% free at 10 years) and six for left-sided obstruction (98% free at 10 years). After 2 years, right-sided obstruction occurred at a rate of about 1% per year and left-sided at a rate of about 0.1% per year. Right ventricular infundibular or valvular obstruction was associated with the aorta and pulmonary trunk positioned side-by-side, coexisting coarctation, use of prosthetic material in sinus reconstruction, one institution, and earlier institutional experience. Pulmonary trunk or pulmonary artery obstruction was associated with lower birth weight, left coronary artery arising from sinus 2, coronary explantation away from the transection site, three institutions, and earlier institutional experience. CONCLUSIONS: A risk-adjusted base incidence (0.5% per year) of reintervention for right-sided obstruction continues late after operation. It is due in part to congenital variability or abnormality of right ventricular outflow structures and to experience and surgeon variability resulting in suboptimal pulmonary trunk reconstruction. The same sources of variability probably affect the aortic root, but its native characteristics plus higher distending pressure make the base incidence considerably less (0.1% per year).

Acute repair of aorta-innominate vein fistulas.

Penetrating wounds of the central vasculature are highly lethal. Ten cases of aorta-left innominate vein fistulas have been reported in the past, but most have presented late after injury. We report three successfully managed cases that had a short interval between injury and repair, and where we used cardiopulmonary bypass with total circulatory arrest. Preoperative arteriography facilitated planning the operative approach. The ready availability of complete radiologic and surgical resources at a trauma center were responsible for the successful outcome of these highly lethal central vascular injuries.

Ventricular to pulmonary artery connections: generalizations.

The basic information about surgically created ventricular to pulmonary artery connections is condensed into five general headings. The information is useful, but is no substitute for the technically competent, well-informed, thoughtful, and intuitive cardiac surgeon.

Factors influencing early and late outcome of the arterial switch operation for transposition of the great arteries.

Between January 1983 and January 1992, 470 patients underwent an arterial switch operation at our institution. An intact (or virtually intact) ventricular septum was present in 278 of 470 (59%); a ventricular septal defect was closed in the remaining 192. Survivals at 1 month and 1, 5, and 8 years among the 470 patients were 93%, 92%, 91%, and 91%, respectively. The hazard function for death (at any time) had a rapidly declining single phase that approached zero by one year after the operation. Risk factors for death included coronary artery patterns with a retropulmonary course of the left coronary artery (two types) and a pattern in which the right coronary artery and left anterior descending arose from the anterior sinus with a posterior course of the circumflex coronary. The only procedural risk factor identified was augmentation of the aortic arch; longer duration of circulatory arrest was also a risk factor for death. Earlier date of operation was a risk factor for death, but only in the case of the senior surgeon. Reinterventions were performed to relieve right ventricular and/or pulmonary artery stenoses alone in 28 patients. The hazard function for reintervention for pulmonary artery or valve stenosis revealed an early phase that peaked at 9 months after the operation and a constant phase for the duration of follow-up. Incremental risk factors for the early phase included multiple ventricular septal defects, the rapid two-stage arterial switch, and a coronary pattern with a single ostium supplying the right coronary and left anterior descending, with a retropulmonary course of the circumflex. The need for reintervention has decreased with time. The arterial switch operation can currently be performed early in life with a low mortality risk (< 5%) and a low incidence of reintervention (< 10%) for supravalvular pulmonary stenosis. The analyses indicate that both the mortality and reintervention risks are lower in patients with less complex anatomy.

Outcomes in seriously ill neonates with coarctation of the aorta. A multiinstitutional study.

Among 326 severely symptomatic neonates with coarctation with or without ventricular septal defect, four died before an initial procedure was performed. Among the 322 undergoing an initial procedure, survival for at least 24 months was 84%; the hazard function for death was lower initially but more prolonged in patients without than in those with ventricular septal defect. Important mitral valve anomalies coexisted in 5% of patients, left ventricular hypoplasia in 5% (more commonly in patients without ventricular septal defect), narrowing of the left ventricular outflow tract in 9% (more common in patients without ventricular septal defect), and narrowing of the proximal arch in 1%; one or more of these anomalies was present in most patients without ventricular septal defect who died. Five percent of the 322 patients had more than one of these coexisting anomalies, and 8% had just one. The most commonly used technique of repair of the coarctation was resection and end-to-end anastomosis, but no technique was a risk factor for death by multivariable analysis. Extension of the area of resection so that the end-to-end anastomosis was proximal to the left subclavian artery but distal to the left common carotid artery did not increase risk; extensions beyond this, and in the case of patch graft repair, extensions proximal to the left subclavian artery, did increase risk. Patch graft repair was associated with the highest prevalence (21%) of reintervention to the coarctation repair. Among patients with coexisting moderate-sized or large ventricular septal defects, repair of the coarctation, pulmonary trunk banding, and subsequent repair of the defect were associated with the highest 2-year survival, 97% in those with single ventricular septal defect. The risk-adjusted outcomes in two institutions were less good than in all others.

Outcomes in patients with interrupted aortic arch and ventricular septal defect. A multiinstitutional study. Congenital Heart Surgeons Society.

Among 183 neonates with interrupted aortic arch and ventricular septal defect entering a multiinstitutional study between 1987 and 1992, nine died before repair was accomplished. Among the remaining 174, survival at 1 month and 1, 3, and 4 years after repair was 73%, 65%, 63%, and 63%, respectively. The risk factors for death were low birth weight, younger age at repair, interrupted arch type B, outlet and trabecular ventricular septal defects, smaller size of the ventricular septal defect, and subaortic narrowing. Echocardiographically measured dimensions (expressed as Z-values) at all levels of the left heart-aorta complex were small. Two among thirty institutions were risk factors, and two others possibly were. Procedural risk factors for death after repair were (1) repair without concomitant procedures in patients with other important levels of obstruction in the left heart-aorta complex, (2) a Damus-Kaye-Stansel anastomosis, and (3) subaortic myotomy/myectomy in the face of subaortic narrowing. One-stage repair plus ascending aorta/arch augmentation had the highest predicted time-related survival in the 20% of patients with interrupted aortic arch and one or more coexisting levels of obstruction in the left heart-aorta complex, as did initial repair without or with aorta/arch augmentation in the 80% without these.

The effect of reperfusion pressure on early outcomes after coronary artery bypass grafting. A randomized trial.

Among 60 patients randomly assigned to a reperfusion pressure of 50 mm Hg or one of 75 mm Hg (30 mm Hg during the first 2 minutes in both groups) during initially hyperkalemic, controlled aortic root reperfusion after coronary artery bypass grafting, no in-hospital deaths occurred, no patient received an intraaortic balloon pump, no patient had new Q waves, and creatine kinase MB release was similar in the two groups. Median interval between the beginning of reperfusion and the return of rhythmic cardiac contractions in the 50 mm Hg group was 7 minutes; in the 75 mm Hg group, it was 5 minutes (P = 0.1). The initial reactive hyperemic response was greater in the 75 mm Hg group. There were no believable differences (P < 0.1) between the two groups in postoperative cardiac output, left and right atrial pressure, arterial blood pressure, and prevalence of catecholamine administration.

Long-term outcome in patients undergoing surgical repair of tetralogy of Fallot.

BACKGROUND: Although corrective surgery for tetralogy of Fallot has been available for more than 30 years, the occurrence of late sudden death in patients in whom surgery was apparently successful remains worrisome. METHODS: We studied long-term survival among 163 patients who survived 30 days after complete repair of tetralogy of Fallot, examining follow-up hospital records and death certificates when relevant. RESULTS: The overall 32-year actuarial survival rate among all patients who survived surgery was 86 percent, as compared with an expected rate of 96 percent in a control population matched for age and sex (P < 0.01). Thirty-year actuarial survival rates were calculated for the patient subgroups. The survival rates among patients less than 5 years old, 5 to 7 years old, and 8 to 11 years old were 90, 93, and 91 percent, respectively--slightly less than the expected rates (P < 0.001, P = 0.06, and P = 0.02). Among patients 12 years old or older at the time of surgery, the survival rate was 76 percent, as compared with an expected rate of 93 percent (P < 0.001). The performance of a palliative Blalock-Taussig shunt procedure before repair, unlike the performance of a Waterston or Potts shunt procedure, was not associated with reduced long-term survival, nor was the need for a trans-annular patch at the time of surgery. Independent predictors of long-term survival were older age at operation (P = 0.02) and a higher ratio of right ventricular to left ventricular systolic pressure after surgery (P = 0.008). Late sudden death from cardiac causes occurred in 10 patients during the 32-year period. CONCLUSIONS: Among patients with surgically repaired tetralogy of Fallot, the rate of long-term survival after the postoperative period is excellent but remains lower than that in the general population. The risk of late sudden death is small.

The future of cardiac surgery.

Cardiac surgery in the future will probably be different than it is today. It is unlikely that the general changes that have occurred in the demands on cardiac surgeons and cardiologists and their responses to them will be reversed. Therefore, it is likely that the role of the primary care physician in decision-making will increase. However, constantly upgraded, properly analyzed, and properly displayed information about the decreasing risks and increasing benefits of cardiac operations needs to be made available to the primary care physician.

Outcomes in critically ill neonates with pulmonary stenosis and intact ventricular septum: a multiinstitutional study. Congenital Heart Surgeons Society.

OBJECTIVE: This study attempted to determine the optimal therapeutic interventions by risk-adjusted comparisons of early and intermediate-term outcomes. BACKGROUND: The variety of interventions and the small case load at individual institutions have delayed the generation of reliable information concerning therapy for this condition. METHODS: In this prospective 27-institution study, 101 neonates were consecutively enrolled (between January 1, 1987 and January 1, 1991). Treatment was determined by the physicians. Demographic and morphologic details were tabulated. Dimensions of the pulmonary "anulus" and tricuspid anulus were measured on echocardiograms, and right ventricular cavity size was estimated. Right ventricular-pulmonary trunk pressure gradients were tabulated. Numerous analyses were made. RESULTS: Severe pulmonary valve stenosis and an intact ventricular septum were present in all patients. The right ventricular-pulmonary trunk junction ("anulus") was severely narrowed in 15%. Right ventricular cavity size was severely reduced in 4%. The tricuspid valve was small in 15% of patients; its diameter was poorly correlated with right ventricular cavity size. Eighty-nine percent and 81% of patients survived > or = 1 month and 4 years, respectively, after the initial procedure. Multivariable analysis identified no patient-specific risk factors for death. Only open pulmonary valvotomy without a support technique was uniformly a procedural risk factor; under some circumstances, transannular patching without a shunt was a risk factor. The right ventricular-pulmonary trunk gradient immediately after valvotomy was < 30 mm Hg in 81% of patients and was similar after surgical and balloon valvotomy. In 74% of patients, no intervention was required after the first accomplished intervention. CONCLUSIONS: Marked variation in morphology is uncommon in critical pulmonary stenosis in neonates. Percutaneous balloon valvotomy and certain types of surgical valvotomy are optimal initial procedures. The unusual situation of a small pulmonary "anulus" may initially require a transannular patch and a systemic-pulmonary artery shunt.

Long-term function of cryopreserved aortic homografts. A ten-year study.

Cryopreserved aortic valve homografts have become an accepted aortic valve substitute, but long-term studies with echocardiographic assessment of valve function are largely unavailable. Between 1981 and January 1, 1991, a total of 178 patients aged 9 months to 80 years (median 46 years) underwent implantation of a cryopreserved aortic valve homograft. Serial two-dimensional Doppler echocardiographic studies were obtained in 149 patients. Overall survival was 91% at 1 year and 85% at 8 years. Survival of patients undergoing isolated primary infracoronary aortic valve replacement was 99% at 1 month and 94% at 8 years. Twelve patients underwent homograft explanation. Freedom from explantation for leaflet degeneration was 95% at 8 years. Freedom from presumed leaflet failure (valve degeneration at explantation or aortic insufficiency grade 3/4 or more without reoperation on echocardiography) was 94% at 5 years and 85% at 8 years. By multivariable analysis younger recipient age was the only risk factor identified for leaflet failure. Ninety-five percent of patients followed up for 4 or more years were in New York Heart Association class I or II.

Outcomes in neonatal pulmonary atresia with intact ventricular septum. A multiinstitutional study.

A total of 171 neonates with pulmonary atresia and intact ventricular septum were entered into a prospective multiinstitutional study between January 1, 1987, and January 1, 1991. Treatment was not assigned randomly but was selected by the responsible physicians. The Z-value (standard deviation units) of the diameter of the tricuspid valve was less than -2 in 52% of patients and less than -4 in 26%; it was highly correlated with right ventricular cavity size (which was small in 90% of patients and was severely reduced in 54%). Coronary artery-right ventricular fistulas were present in 45% of patients, and right ventricular dependency was severe in 9%; diameter (Z-value) of the tricuspid valve was negatively correlated (P < 0.0001) with the prevalence of both. Survival was 81% at 1 month after the first intervention and 64% at 4 years; the hazard function (instantaneous risk of death) declined rapidly after the initial procedure but remained appreciable for 24 months. Multivariable analysis showed small diameter of the tricuspid valve, severe right ventricular coronary dependency, birth weight, and the date and type of initial procedure to be risk factors for time-related death. Subsequent procedures were performed in 51% of patients. Among patients undergoing an initial procedure that did not include a systemic-pulmonary artery shunt, only 49% did not receive a shunt in the subsequent 1 month; small size of the tricuspid valve was the only risk factor for receiving the subsequent shunt. Ninety-eight percent of living patients whose initial procedure did not include a transannular patch were free of a subsequently placed transannular patch within 1 month, but only 45% were free of it 3 years later; no risk factors were identified. Eighteen percent of living patients had received a one-ventricle repair within 3 years, and 32% had received a two-ventricle repair; the remainder (50%) had incompletely separated pulmonary and systemic circulations. The only patient-specific risk factor for not receiving a two-ventricle repair was the Z-value of the tricuspid valve.

When and how to include arch repair in patients with acute dissections involving the ascending aorta.

The arch should be included in the repair in patients with acute aortic dissection involving the ascending aorta when (1) the intimal tear is in the arch, (2) rupture of the arch has occurred, (3) the outer wall of the false channel in the arch is tenuous, and (4) the inner wall of the false channel is fragmented. A technique has evolved for patients with acute aortic dissection involving the arch that seems to minimize the difficulties and risks of including the arch, when indicated. Its place will best be determined by additional, prospective, and preferably multi-institutional testing.