Meena Nathan

Electrocardiographic monitoring for detecting atrial fibrillation after ischemic stroke or transient ischemic attack: systematic review and meta-analysis.

Background—Atrial fibrillation (AF) is a major cause of stroke. Although standard investigations after an event include electrocardiographic monitoring, the optimal duration to detect AF is unclear. We performed a systematic review and meta-analysis to determine whether the duration of electrocardiographic monitoring after an ischemic event is related to the detection of AF. Methods and Results—Prospective studies that reported the proportion of new AF diagnosed using electrocardiographic monitoring for >12 hours in patients with recent stroke or transient ischemic attack were analyzed. Studies were excluded if the stroke was hemorrhagic or AF was previously diagnosed. A total of 31 articles met inclusion criteria. Longer duration of monitoring was associated with an increased detection of AF when examining monitoring time as a continuous variable (P<0.001 for metaregression analysis). When dichotomizing studies based on monitoring duration, studies with monitoring lasting ⩽72 hours detected AF in 5.1%, whereas monitoring lasting ≥7 days detected AF in 15%. The proportion of new diagnosis increased to 29.15% with extended monitoring for 3 months. Significant heterogeneity within studies was detected for both groups (⩽72 hours, I2=91.3%; ≥7 days, I2=75.8). When assessing the odds of AF detection in the 3 randomized controlled trial, there was a 7.26 increased odds of AF with long-term monitoring (95% confidence intervals [3.99–12.83]; P value <0.001). Conclusions—Longer duration of electrocardiographic monitoring after cryptogenic stroke is associated with a greater detection of AF. Future investigation is needed to determine the optimal duration of long-term monitoring.

Surgical technical performance scores are predictors of late mortality and unplanned reinterventions in infants after cardiac surgery

OBJECTIVE We have previously shown that surgical Technical Performance Scores (TPS) are important predictors of early postoperative morbidity across a wide spectrum of procedures and that intraoperative recognition and intervention of residual defects resulted in improved outcomes. We hypothesized that these scores would also be important predictors of midterm outcomes. METHODS Neonates and infants aged younger 6 months were prospectively followed from the index surgery for a minimum of 1 year. The TPS were calculated using previously published criteria, including intraoperative course, predischarge echocardiograms or catheterizations, and clinical data, and graded as optimal, adequate, or inadequate. Case complexity was determined by the Risk Adjustment for Congenital Heart Surgery-1 category. The primary outcome was mortality, and the secondary outcome was the need for unplanned reinterventions. Outcomes were analyzed using nonparametric methods and a logistic regression model. RESULTS A total of 166 patients were included in our study, with 7 early deaths. The remaining 159 patients (Risk Adjustment for Congenital Heart Surgery-1 category 4-6, 76 [48%]; neonates, 78 [49%]) were followed for a minimum of 1 year after surgery. There were 14 late deaths or late transplantations and 55 late reinterventions. On univariate analysis, the TPS were associated with mortality (P < .001) and reintervention (P = .04). On logistic regression analysis, inadequate TPS was associated with late mortality (P < .001; odds ratio, 7.2; 95% confidence interval, 2.2-23.6), and Risk Adjustment for Congenital Heart Surgery-1 category (P = .004; odds ratio, 3.7; 1.5-8.8) at index surgery was associated with need for late unplanned reintervention. CONCLUSIONS Technical performance affects midterm survival after infant heart surgery. Inadequate TPS can be used to prospectively identify patients at ongoing risk of demise and the need for reintervention. An aggressive approach to diagnosing and treating residual lesions at the initial operation is warranted.

Intraoperative adverse events can be compensated by technical performance in neonates and infants after cardiac surgery: A prospective study

OBJECTIVE Our objective was to define the relationship between surgical technical performance score, intraoperative adverse events, and major postoperative adverse events in complex pediatric cardiac repairs. METHOD Infants younger than 6 months were prospectively followed up until discharge from the hospital. Technical performance scores were graded as optimal, adequate, or inadequate based on discharge echocardiograms and need for reintervention after initial surgery. Case complexity was determined by Risk Adjustment in Congenital Heart Surgery (RACHS-1) category, and preoperative illness severity was assessed by Pediatric Risk of Mortality (PRISM) III score. Intraoperative adverse events were prospectively monitored. Outcomes were analyzed using nonparametric methods and a logistic regression model. RESULTS A total of 166 patients (RACHS 4-6 [49%]), neonates [50%]) were observed. Sixty-one (37%) had at least 1 intraoperative adverse event, and 47 (28.3%) had at least 1 major postoperative adverse event. There was no correlation between intraoperative adverse events and RACHS, preoperative PRISM III, technical performance score, or postoperative adverse events on multivariate analysis. For the entire cohort, better technical performance score resulted in lower postoperative adverse events, lower postoperative PRISM, and lower length of stay and ventilation time (P < .001). Patients requiring intraoperative revisions fared as well as patients without, provided the technical score was at least adequate. CONCLUSIONS In neonatal and infant open heart repairs, technical performance score is one of the main predictors of postoperative morbidity. Outcomes are not affected by intraoperative adverse events, including surgical revisions, provided technical performance score is at least adequate.

Change in regional (somatic) near-infrared spectroscopy is not a useful indictor of clinically detectable low cardiac output in children after surgery for congenital heart defects

Objective: Near-infrared spectroscopy correlation with low cardiac output has not been validated. Our objective was to determine role of splanchnic and/or renal oxygenation monitoring using near-infrared spectroscopy for detection of low cardiac output in children after surgery for congenital heart defects. Design: Prospective observational study. Setting: Pediatric intensive care unit of a tertiary care teaching hospital. Patients: Children admitted to the pediatric intensive care unit after surgery for congenital heart defects. Interventions: None. Measurements and Main Results: We hypothesized that splanchnic and/or renal hypoxemia detected by near-infrared spectroscopy is a marker of low cardiac output after pediatric cardiac surgery. Patients admitted after cardiac surgery to the pediatric intensive care unit over a 10-month period underwent serial splanchnic and renal near-infrared spectroscopy measurements until extubation. Baseline near-infrared spectroscopy values were recorded in the first postoperative hour. A near-infrared spectroscopy event was a priori defined as ≥20% drop in splanchnic and/or renal oxygen saturation from baseline during any hour of the study. Low cardiac output was defined as metabolic acidosis (pH <7.25, lactate >2 mmol/L, or base excess ⩽−5), oliguria (urine output <1 mL/kg/hr), or escalation of inotropic support. Receiver operating characteristic analysis was performed using near-infrared spectroscopy event as a diagnostic test for low cardiac output. Twenty children were enrolled: median age was 5 months; median Risk Adjustment for Congenital Heart Surgery category was 3 (1–6); median bypass and cross-clamp times were 120 mins (45–300 mins) and 88 mins (17–157 mins), respectively. Thirty-one episodes of low cardiac output and 273 near-infrared spectroscopy events were observed in 17 patients. The sensitivity and specificity of a near-infrared spectroscopy event as an indicator of low cardiac output were 48% (30%–66%) and 67% (64%–70%), respectively. On receiver operating characteristic analysis, neither splanchnic nor renal near-infrared spectroscopy event had a significant area under the curve for prediction of low cardiac output (area under the curve: splanchnic 0.45 [95% confidence interval 0.30–0.60], renal 0.51 [95% confidence interval 0.37–0.65]). Conclusions: Splanchnic and/or renal hypoxemia as detected by near-infrared spectroscopy may not be an accurate indicator of low cardiac output after surgery for congenital heart defects.

Technical performance score is associated with outcomes after the Norwood procedure

OBJECTIVES The technical performance score (TPS) has been reported in a single center study to predict the outcomes after congenital cardiac surgery. We sought to determine the association of the TPS with outcomes in patients undergoing the Norwood procedure in the Single Ventricle Reconstruction trial. METHODS We calculated the TPS (class 1, optimal; class 2, adequate; class 3, inadequate) according to the predischarge echocardiograms analyzed in a core laboratory and unplanned reinterventions that occurred before discharge from the Norwood hospitalization. Multivariable regression examined the association of the TPS with interval to first extubation, Norwood length of stay, death or transplantation, unplanned postdischarge reinterventions, and neurodevelopment at 14 months old. RESULTS Of 549 patients undergoing a Norwood procedure, 356 (65%) had an echocardiogram adequate to assess atrial septal restriction or arch obstruction or an unplanned reintervention, enabling calculation of the TPS. On multivariable regression, adjusting for preoperative variables, a better TPS was an independent predictor of a shorter interval to first extubation (P=.019), better transplant-free survival before Norwood discharge (P<.001; odds ratio, 9.1 for inadequate vs optimal), shorter hospital length of stay (P<.001), fewer unplanned reinterventions between Norwood discharge and stage II (P=.004), and a higher Bayley II psychomotor development index at 14 months (P=.031). The TPS was not associated with transplant-free survival after Norwood discharge, unplanned reinterventions after stage II, or the Bayley II mental development index at 14 months. CONCLUSIONS TPS is an independent predictor of important outcomes after Norwood and could serve as a tool for quality improvement.

Inadequate technical performance scores are associated with late mortality and late reintervention.

BACKGROUND We have shown previously that technical performance score (TPS) is strongly associated with early mortality and major postoperative adverse events in a diverse group of patients. We now report evaluation of the validity of TPS in predicting late outcomes in the same group of patients. METHODS Patients who underwent surgery between June 1, 2005 and June 30, 2006 were included. The TPS were assigned based on discharge echocardiograms and certain clinical criteria as previously described. Follow-up data for up to 4 years were retrospectively collected. Cox proportional hazards models were used for analysis. RESULTS A total of 679 patients were included in the analysis. One hundred twenty-three (18%) were neonates, 213 (31%) infants, 291 (435) children, and 52 (8%) adults. Four hundred ninety-one (72%) were in low-risk adjustment in congenital heart surgery (RACHS; 1 to 3), 109 (16%) in high risk (4 to 6), and 27 (4%) were less than 18 years and could not be assigned a RACHS score. Three hundred thirty-one (48%) had an optimal TPS, 283 (42%) adequate, 61 (9%) inadequate, and 4 (1%) could not be scored. There were 34 (5%) late deaths and 149 (22%) late unplanned reinterventions. By univariate analysis, age, RACHS-1 categories, and TPS were all significantly associated with late reintervention (p < 0.001 for all), while TPS and RACHS-1 were significant factors for mortality (p < 0.001). On multivariable modeling, inadequate TPS was strongly associated with both late mortality (p = 0.001; HR [hazard ratio] 3.8, CI [confidence interval] 1.7 to 8.4) and late reintervention (p = 0.002, HR 2.1, CI 1.3 to 3.3) after controlling for RACHS-1 and age. CONCLUSIONS The TPS has a strong association with late outcomes across a wide range of age and disease complexity and may serve as a tool to identify patients who are at a higher risk for late reintervention or mortality.

Mortality in hypoplastic left heart syndrome: Review of 216 autopsy cases of aortic atresia with attention to coronary artery disease

OBJECTIVES Aortic atresia (AA) in hypoplastic left heart syndrome (HLHS) has been associated with increased mortality in several prior studies. We reviewed our autopsy series to explore the relationship of coronary abnormalities to anatomic subsets of HLHS with AA. METHODS We retrospectively reviewed all pathology specimens with AA/MS (mitral stenosis) and AA/MA (mitral atresia) in the Cardiac Registry of Childrens Hospital Boston between 1955 and 2009 including autopsy reports, operative notes, and imaging studies. Formalin-fixed hearts were examined, and cases found to have macroscopic coronary artery abnormalities were sectioned at mid-left ventricular level in the transverse plane and at mid-right ventricular level in the longitudinal plane for histologic analysis of coronary arteries using tissue sections stained with hematoxylin and eosin. RESULTS A total of 216 autopsy cases were identified with AA/MS (134) and AA/MA (82). Coronary anomalies were found in 49 cases, left ventricle-coronary fistula in 39, all in AA/MS, and 10 other coronary abnormalities, all in AA/MA. Histologic study confirmed fistulas only in the AA/MS group with no evidence of fistulas in the AA/MA group. CONCLUSIONS The occurrence of left ventricle-coronary fistulas appears limited to the AA/MS group, and coronary fistula specimens were disproportionately more prevalent in postoperative specimens. Further clinical studies are required to validate this finding and to identify subgroups that carry a higher mortality risk.

Myocardial Hypertrophy Overrides the Angiogenic Response to Hypoxia

Background Cyanosis and myocardial hypertrophy frequently occur in combination. Hypoxia or cyanosis can be potent inducers of angiogenesis, regulating the expression of hypoxia-inducible factors (HIF), vascular endothelial growth factors (VEGF), and VEGF receptors (VEGFR-1 and 2); in contrast, pressure overload hypertrophy is often associated with impaired pro-angiogenic signaling and decreased myocardial capillary density. We hypothesized that the physiological pro-angiogenic response to cyanosis in the hypertrophied myocardium is blunted through differential HIF and VEGF-associated signaling. Methods and Results Newborn rabbits underwent aortic banding and, together with sham-operated littermates, were transferred into a hypoxic chamber (FiO2 = 0.12) at 3 weeks of age. Control banded or sham-operated rabbits were housed in normoxia. Systemic cyanosis was confirmed (hematocrit, arterial oxygen saturation, and serum erythropoietin). Myocardial tissue was assayed for low oxygen concentrations using a pimonidazole adduct. At 4 weeks of age, HIF-1α and HIF-2α protein levels, HIF-1α DNA-binding activity, and expression of VEGFR-1, VEGFR-2, and VEGF were determined in hypoxic and normoxic rabbits. At 6 weeks of age, left-ventricular capillary density was assessed by immunohistochemistry. Under normoxia, capillary density was decreased in the banded rabbits compared to non-banded littermates. As expected, non-hypertrophied hearts responded to hypoxia with increased capillary density; however, banded hypoxic rabbits demonstrated no increase in angiogenesis. This blunted pro-angiogenic response to hypoxia in the hypertrophied myocardium was associated with lower HIF-2α and VEGFR-2 levels and increased HIF-1α activity and VEGFR-1 expression. In contrast, non-hypertrophied hearts responded to hypoxia with increased HIF-2α and VEGFR-2 expression with lower VEGFR-1 expression. Conclusion The participation of HIF-2α and VEGFR-2 appear to be required for hypoxia-stimulated myocardial angiogenesis. In infant rabbit hearts with pressure overload hypertrophy, this pro-angiogenic response to hypoxia is effectively uncoupled, apparently in part due to altered HIF-mediated signaling and VEGFR subtype expression.

Technical Performance Scores in Congenital Cardiac Operations: A Quality Assessment Initiative

BACKGROUND Technical performance in congenital cardiac operations and its association with clinical outcomes was previously examined in infants and neonates. The purpose of this study was the development and implementation of a system for measuring technical performance in the majority of congenital cardiac operations to be used as a surgeons self-assessment tool. METHODS Using the methodologic framework piloted at our institution, measures of technical performance were created for more than 90% of all congenital cardiac operations. Each operation was divided into multiple subprocedures to be assessed separately. Criteria for technical scores were created using a consensus panel of senior clinicians and were based primarily on the predischarge echocardiographic findings and need for early postoperative reinterventions. This system of procedure modules was then piloted by prospectively assigning technical scores to all patients undergoing operations. RESULTS Thirty modules were created covering more than 90% of the cardiac operations performed. One hundred eighty-five patients were enlisted. One hundred one (54.6%) cases were scored as class 1 (highest), 46 (24.9%) cases as class 2, 22 (11.9%) cases as class 3 (lowest); 16 cases (8.6%) could not be scored. The results were further analyzed by RACHS (Risk Adjustment for Congenital Heart Surgery) categories and outcomes. Valve-procedure-specific criteria were calibrated to reflect specific echocardiographic measurements. CONCLUSIONS The development and implementation of a broad technical performance self-assessment system for congenital cardiac operations is possible. Based on this scoring system, the impact of a less than optimal (2 or 3) technical score depends on case risk category, with higher mortality in the higher risk group, and increased resource use for lower risk procedures.

Hepatic duct confluence injury in blunt abdominal trauma: case report and synopsis on management.

Injuries of the extra hepatic biliary tree following blunt trauma to the abdomen are rare. We present here a case of injury to the confluence of the hepatic ducts and a brief synopsis on diagnosis and management of blunt injury to the extrahepatic biliary system.