Prakash P Punjabi

Rapid detection of acute kidney injury by plasma and urinary neutrophil gelatinase-associated lipocalin after cardiopulmonary bypass.

Background: Cardiopulmonary bypass (CPB) is associated with a significant risk of postoperative renal dysfunction. We studied the utility of a novel biomarker in predicting acute kidney injury (AKI) in adult patients undergoing cardiac surgery. Methods and Results: Blood and urine were obtained from 50 patients undergoing CPB-requiring surgery. Patients were divided into group A (n = 41) with normal creatinine pre-bypass and post-bypass and group B (n = 9) who developed an increase in serum creatinine of >0.5 mg/dL within the first 48 hours post CPB. Plasma and urinary neutrophil gelatinase-associated lipocalin (NGAL) was determined at baseline and 2 hours after CPB. Plasma levels of NGAL were higher in patients who developed AKI [214 ± 16.7 ng/mL (95% CI 176.9-252.9)] compared with those who did not [149.5 ± 13.5 ng/mL (95% CI 122.1-175.7); P = 0.035]. Two hours after CPB, there was a significant increase (P = 0.0003) in NGAL levels, greater in those patients who developed AKI [476.1 ± 41.1 ng/mL (95% CI 380.6-571.6); P = 0.0003] compared with those who did not [278.4 ± 22 ng/mL (95% CI 233.9-323.0)]. In the AKI group, urinary NGAL increased from 7.13 ± 2.30 ng/mL (95% CI 2.5-11.8) to 2924 ± 786 ng/mL (95% CI 1110-4739). In the non-AKI group, there was an increase from 1.6 ± 0.6 (95% CI 0.3-3.0) to 749 ± 179 ng/mL (95% CI 386-1113). The post-CPB levels of urinary NGAL were significantly different in the AKI group (P < 0.0001) such that a suitable threshold for use as a diagnostic test could be determined. Receiver operating characteristics were determined for plasma and urinary NGAL with area under the curve (AUC) of 0.80 and 0.96, respectively. For a threshold of 433 ng/mmol creatinine, the test had 90% sensitivity and 78% specificity for the detection of post-CPB renal dysfunction. Conclusions: Measurement of this novel biomarker in the urine or plasma of patients in the first hours after CPB is predictive of subsequent renal injury. Although the AUC for plasma NGAL seemed inferior to urine, even an AUC of 0.8 as reported compares very favorably to that for other “outstanding” biomarkers (eg, AUCs in the 0.7 range for troponin).

Integrated genomic approaches implicate osteoglycin (Ogn) in the regulation of left ventricular mass

Left ventricular mass (LVM) and cardiac gene expression are complex traits regulated by factors both intrinsic and extrinsic to the heart. To dissect the major determinants of LVM, we combined expression quantitative trait locus and quantitative trait transcript (QTT) analyses of the cardiac transcriptome in the rat. Using these methods and in vitro functional assays, we identified osteoglycin (Ogn) as a major candidate regulator of rat LVM, with increased Ogn protein expression associated with elevated LVM. We also applied genome-wide QTT analysis to the human heart and observed that, out of ∼22,000 transcripts, OGN transcript abundance had the highest correlation with LVM. We further confirmed a role for Ogn in the in vivo regulation of LVM in Ogn knockout mice. Taken together, these data implicate Ogn as a key regulator of LVM in rats, mice and humans, and suggest that Ogn modifies the hypertrophic response to extrinsic factors such as hypertension and aortic stenosis.

Epigenome-wide association of DNA methylation markers in peripheral blood from Indian Asians and Europeans with incident type 2 diabetes: a nested case-control study.

BACKGROUND Indian Asians, who make up a quarter of the worlds population, are at high risk of developing type 2 diabetes. We investigated whether DNA methylation is associated with future type 2 diabetes incidence in Indian Asians and whether differences in methylation patterns between Indian Asians and Europeans are associated with, and could be used to predict, differences in the magnitude of risk of developing type 2 diabetes. METHODS We did a nested case-control study of DNA methylation in Indian Asians and Europeans with incident type 2 diabetes who were identified from the 8-year follow-up of 25 372 participants in the London Life Sciences Prospective Population (LOLIPOP) study. Patients were recruited between May 1, 2002, and Sept 12, 2008. We did epigenome-wide association analysis using samples from Indian Asians with incident type 2 diabetes and age-matched and sex-matched Indian Asian controls, followed by replication testing of top-ranking signals in Europeans. For both discovery and replication, DNA methylation was measured in the baseline blood sample, which was collected before the onset of type 2 diabetes. Epigenome-wide significance was set at p<1 × 10(-7). We compared methylation levels between Indian Asian and European controls without type 2 diabetes at baseline to estimate the potential contribution of DNA methylation to increased risk of future type 2 diabetes incidence among Indian Asians. FINDINGS 1608 (11·9%) of 13 535 Indian Asians and 306 (4·3%) of 7066 Europeans developed type 2 diabetes over a mean of 8·5 years (SD 1·8) of follow-up. The age-adjusted and sex-adjusted incidence of type 2 diabetes was 3·1 times (95% CI 2·8-3·6; p<0·0001) higher among Indian Asians than among Europeans, and remained 2·5 times (2·1-2·9; p<0·0001) higher after adjustment for adiposity, physical activity, family history of type 2 diabetes, and baseline glycaemic measures. The mean absolute difference in methylation level between type 2 diabetes cases and controls ranged from 0·5% (SD 0·1) to 1·1% (0·2). Methylation markers at five loci were associated with future type 2 diabetes incidence; the relative risk per 1% increase in methylation was 1·09 (95% CI 1·07-1·11; p=1·3 × 10(-17)) for ABCG1, 0·94 (0·92-0·95; p=4·2 × 10(-11)) for PHOSPHO1, 0·94 (0·92-0·96; p=1·4 × 10(-9)) for SOCS3, 1·07 (1·04-1·09; p=2·1 × 10(-10)) for SREBF1, and 0·92 (0·90-0·94; p=1·2 × 10(-17)) for TXNIP. A methylation score combining results for the five loci was associated with future type 2 diabetes incidence (relative risk quartile 4 vs quartile 1 3·51, 95% CI 2·79-4·42; p=1·3 × 10(-26)), and was independent of established risk factors. Methylation score was higher among Indian Asians than Europeans (p=1 × 10(-34)). INTERPRETATION DNA methylation might provide new insights into the pathways underlying type 2 diabetes and offer new opportunities for risk stratification and prevention of type 2 diabetes among Indian Asians. FUNDING The European Union, the UK National Institute for Health Research, the Wellcome Trust, the UK Medical Research Council, Action on Hearing Loss, the UK Biotechnology and Biological Sciences Research Council, the Oak Foundation, the Economic and Social Research Council, Helmholtz Zentrum Munchen, the German Research Center for Environmental Health, the German Federal Ministry of Education and Research, the German Center for Diabetes Research, the Munich Center for Health Sciences, the Ministry of Science and Research of the State of North Rhine-Westphalia, and the German Federal Ministry of Health.

Abnormal myocardial insulin signalling in type 2 diabetes and left-ventricular dysfunction

AIMS Whole body and myocardial insulin resistance are features of non-insulin-dependent diabetes mellitus (NIDDM) and left-ventricular dysfunction (LVD). We determined whether abnormalities of insulin receptor substrate-1 (IRS1), IRS1-associated PI3K (IRS1-PI3K), and glucose transporter 4 (GLUT4) contribute to tissue-specific insulin resistance. METHODS AND RESULTS We collected skeletal muscle (n = 27) and myocardial biopsies (n = 24) from control patients (n = 7), patients with NIDDM (n = 9) and patients with LVD (n = 8), who were characterized by euglycaemic-hyperinsulinaemic clamp and positron emission tomography. Comparative studies were carried out in three mouse models. We demonstrate an unrecognized reduction of IRS1 in skeletal muscle of LVD patients and an unexpected increase in cardiac IRS1-PI3K activity in NIDDM and LVD patients. In NIDDM, there was a concomitant reduction in sarcolemmal GLUT4, whereas in patients with LVD sarcolemmal GLUT4 was increased. We confirm activation of IRS1-PI3K and reduction in sarcolemmal GLUT4 in the insulin resistant ob/ob mouse heart where we also demonstrate perturbation of GLUT4 docking and fusion. A direct relationship between PI3K and GLUT4 was demonstrated in mice expressing activated PI3K in the heart and increased GLUT4 at the sarcolemma was confirmed in a mouse model of LVD. CONCLUSION Our data show that the mechanisms of myocardial insulin resistance are different between NIDDM and LVD.

Linee guida ESC 2015 per il trattamento dell'endocardite infettiva: Task Force per il Trattamento dell'Endocardite Infettiva della Società Europea di Cardiologia (ESC): Con il patrocinio dell'Associazione Europea di Chirurgia Cardiotoracica (EACTS) e dell'Associazione Europea di Medicina Nucleare (EANM)

Authors/Task Force Members: Gilbert Habib* (Chairperson) (France), Patrizio Lancellotti* (co-Chairperson) (Belgium), Manuel J. Antunes (Portugal), Maria Grazia Bongiorni (Italy), Jean-Paul Casalta (France), Francesco Del Zotti (Italy), Raluca Dulgheru (Belgium), Gebrine El Khoury (Belgium), Paola Anna Erba (Italy), Bernard Iung (France), Jose M. Miro (Spain), Barbara J. Mulder (The Netherlands), Edyta Plonska-Gosciniak (Poland), Susanna Price (UK), Jolien Roos-Hesselink (The Netherlands), Ulrika Snygg-Martin (Sweden), Franck Thuny (France), Pilar Tornos Mas (Spain), Isidre Vilacosta (Spain), and Jose Luis Zamorano (Spain)Autori/Membri della Task Force Gilbert Habib (Chairperson) (Francia), Patrizio Lancellotti (co-Chairperson) (Belgio), Manuel J. Antunes (Portogallo), Maria Grazia Bongiorni (Italia), Jean-Paul Casalta (Francia), Francesco Del Zotti (Italia), Raluca Dulgheru (Belgio), Gebrine El Khoury (Belgio), Paola Anna Erbaa (Italia), Bernard Iung (Francia), Jose M. Mirob (Spagna), Barbara J. Mulder (Olanda), Edyta Plonska-Gosciniak (Polonia), Susanna Price (UK), Jolien Roos-Hesselink (Olanda), Ulrika Snygg-Martin (Svezia), Franck Thuny (Francia), Pilar Tornos Mas (Spagna), Isidre Vilacosta (Spagna), Jose Luis Zamorano (Spagna)

An evaluation of existing risk stratification models as a tool for comparison of surgical performances for coronary artery bypass grafting between institutions

OBJECTIVE Risk stratification systems are used in cardiac surgery to estimate mortality risk for individual patients and to compare surgical performance between institutions or surgeons. This study investigates the suitability of six existing risk stratification systems for these purposes. METHODS Data on 5471 patients who underwent isolated coronary artery bypass grafting at two UK cardiac centres between 1993 and 1999 were extracted from a prospective computerised clinical data base. Of these patients, 184 (3.3%) died in hospital. In-hospital mortality risk scores were calculated for each patient using the Parsonnet score, the EuroSCORE, the ACC/AHA score and three UK Bayes models (old, new complex and new simple). The accuracy for predicting mortality at an institutional level was assessed by comparing total observed and predicted mortality. The accuracy of the risk scores for predicting mortality for a patient was assessed by the Hosmer-Lemeshow test. The receiver operating characteristic (ROC) curve was used to evaluate how well a system ranks the patient with respect to their risk of mortality and can be useful for patient management. RESULTS Both EuroSCORE and the simple Bayes model were reasonably accurate at predicting overall mortality. However predictive accuracy at the patient level was poor for all systems, although EuroSCORE was accurate for low to medium risk patients. Discrimination was fair with the following ROC areas: Parsonnet 0.73, EuroSCORE 0.76, ACC/AHA system 0.76, old Bayes 0.77, complex Bayes 0.76, simple Bayes 0.76. CONCLUSIONS This study suggests that two of the scores may be useful in comparing institutions. None of the risk scores provide accurate risk estimates for individual patients in the two hospitals studied although EuroSCORE may have some utility for certain patients. All six systems perform moderately at ranking the patients and so may be useful for patient management. More results are needed from other institutions to confirm that the EuroSCORE and the simple Bayes model are suitable for institutional risk-adjusted comparisons.

Lipomatous hypertrophy of the interatrial septum: a commonly misdiagnosed mass often leading to unnecessary cardiac surgery

Lipomatous hypertrophy of the interatrial septum is a benign cardiac mass that should be considered as part of the differential diagnosis for any atrial cardiac tumour. In the reported case, this lesion was initially suspected to be malignant and the patient was thus referred directly to cardiac surgeons for surgical removal. Unnecessary surgical intervention was swiftly averted because the cardiac surgeon promptly referred the patient for an expert echocardiogram that confirmed the diagnosis of lipomatous hypertrophy. The authors discuss the characteristic features of this lesion and how the diagnosis may be made based on several non-invasive imaging modalities without the need for a tissue biopsy. This condition is more common than initially thought and remains under-recognised by most clinicians. In such cases an increased awareness of this lesion along with the opinion of a specialist echocardiologist would help to avoid a misdiagnosis and unnecessary intervention.

Surgical and interventional management of mitral valve regurgitation: a position statement from the European Society of Cardiology Working Groups on Cardiovascular Surgery and Valvular Heart Disease

Mitral regurgitation (MR) has a prevalence of 2% in the general population and is even more common in the elderly.[1][1] Organic (or primary) MR arises as a result of pathology affecting one or more components of the mitral valve (MV) apparatus, whereas functional (or secondary) MR is a consequence

Microdomain-Specific Modulation of L-type Calcium Channels Leads to Triggered Ventricular Arrhythmia in Heart Failure

Supplemental Digital Content is available in the text.

Direct Evidence for Microdomain-Specific Localization and Remodeling of Functional L-Type Calcium Channels in Rat and Human Atrial Myocytes

Background— Distinct subpopulations of L-type calcium channels (LTCCs) with different functional properties exist in cardiomyocytes. Disruption of cellular structure may affect LTCC in a microdomain-specific manner and contribute to the pathophysiology of cardiac diseases, especially in cells lacking organized transverse tubules (T-tubules) such as atrial myocytes (AMs). Methods and Results— Isolated rat and human AMs were characterized by scanning ion conductance, confocal, and electron microscopy. Half of AMs possessed T-tubules and structured topography, proportional to cell width. A bigger proportion of myocytes in the left atrium had organized T-tubules and topography than in the right atrium. Super-resolution scanning patch clamp showed that LTCCs distribute equally in T-tubules and crest areas of the sarcolemma, whereas, in ventricular myocytes, LTCCs primarily cluster in T-tubules. Rat, but not human, T-tubule LTCCs had open probability similar to crest LTCCs, but exhibited ≈40% greater current. Optical mapping of Ca2+ transients revealed that rat AMs presented ≈3-fold as many spontaneous Ca2+ release events as ventricular myocytes. Occurrence of crest LTCCs and spontaneous Ca2+ transients were eliminated by either a caveolae-targeted LTCC antagonist or disrupting caveolae with methyl-&bgr;-cyclodextrin, with an associated ≈30% whole-cell ICa,L reduction. Heart failure (16 weeks post–myocardial infarction) in rats resulted in a T-tubule degradation (by ≈40%) and significant elevation of spontaneous Ca2+ release events. Although heart failure did not affect LTCC occurrence, it led to ≈25% decrease in T-tubule LTCC amplitude. Conclusions— We provide the first direct evidence for the existence of 2 distinct subpopulations of functional LTCCs in rat and human AMs, with their biophysical properties modulated in heart failure in a microdomain-specific manner.