Position statement from the Indian Society of Gastroenterology, Cardiological Society of India, Indian Academy of Neurology and Vascular Society of India on gastrointestinal bleeding and endoscopic procedures in patients on antiplatelet and/or anticoagulant therapy

Antiplatelet and/or anticoagulant agents (collectively known as antithrombotic agents) are used to reduce the risk of thromboembolic events in patients with conditions such as atrial fibrillation, acute coronary syndrome, recurrent stroke prevention, deep vein thrombosis, hypercoagulable states and endoprostheses. Antithrombotic-associated gastrointestinal (GI) bleeding is an increasing burden due to the growing population of advanced age with multiple comorbidities and the expanding indications for the use of antiplatelet agents and anticoagulants. GI bleeding in antithrombotic users is associated with an increase in short-term and long-term mortality. In addition, in recent decades, there has been an exponential increase in the use of diagnostic and therapeutic GI endoscopic procedures. Since endoscopic procedures hold an inherent risk of bleeding that depends on the type of endoscopy and patients' comorbidities, in patients already on antithrombotic therapies, the risk of procedure-related bleeding is further increased. Interrupting or modifying doses of these agents prior to any invasive procedures put these patients at increased risk of thromboembolic events. Although many international GI societies have published guidelines for the management of antithrombotic agents during an event of GI bleeding and during urgent and elective endoscopic procedures, no Indian guidelines exist that cater to Indian gastroenterologists and their patients. In this regard, the Indian Society of Gastroenterology (ISG), in association with the Cardiological Society of India (CSI), Indian Academy of Neurology (IAN) and Vascular Society of India (VSI), have developed a "Guidance Document" for the management of antithrombotic agents during an event of GI bleeding and during urgent and elective endoscopic procedures.

A common Matrix metalloproteinase 8 promoter haplotype enhances the risk for hypertension via diminished interactions with nuclear factor kappa B

OBJECTIVES

Matrix metalloproteinase 8 (MMP8) has a prominent role in collagen turnover in blood vessels and vascular remodeling. The contribution of regulatory single nucleotide polymorphisms in MMP8 to cardiovascular diseases is unclear. We aimed to delineate the influence of MMP8 promoter variations on hypertension.

METHODS

A case-control study in unrelated individuals ( n  = 2565) was carried out. Resequencing of the MMP8 proximal promoter, linkage disequilibrium analysis, genotyping of variants and regression analyses were performed. MMP8 promoter-reporter constructs were generated and expressed in human vascular endothelial cells under various conditions.

RESULTS

We identified four single nucleotide polymorphisms (SNPs) in the promoter region of MMP8 : -1089A/G (rs17099452), -815G/T (rs17099451), -795C/T (rs11225395), -763A/T (rs35308160); these SNPs form three major haplotypes. Hap3 (viz., GTTT haplotype) carriers showed significant associations with hypertension in two geographically distinct human populations (e.g., Chennai: odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.16-1.86, P  = 2 × 10 -3 ; Chandigarh: OR = 1.85, 95% CI = 1.21-2.81, P  = 4 × 10 -3 ). Hap3 carriers also displayed elevated systolic blood pressure, diastolic blood pressure and mean arterial pressure levels. Hap3 promoter-reporter construct showed lower promoter activity than the wild-type (Hap1) construct. In silico analysis and molecular dynamics studies predicted diminished binding of the transcription factor nuclear factor kappa B (NF-κB) to the functional -815T allele of Hap3 compared to the -815G wild-type allele; this prediction was validated by in-vitro experiments. Hap3 displayed impaired response to tumor necrosis factor-alpha treatment, possibly due to weaker binding of NF-κB. Notably, MMP8 promoter haplotypes were identified as independent predictors of plasma MMP8 and endothelial dysfunction markers (von Willebrand factor and endothelin-1) levels.

CONCLUSION

MMP8 promoter GTTT haplotype has a functional role in reducing MMP8 expression during inflammation via diminished interaction with NF-κB and in enhancing the risk of hypertension.

Functional Gly297Ser Variant of the Physiological Dysglycemic Peptide Pancreastatin Is a Novel Risk Factor for Cardiometabolic Disorders

Pancreastatin (PST), a chromogranin A-derived potent physiological dysglycemic peptide, regulates glucose/insulin homeostasis. We have identified a nonsynonymous functional PST variant (p.Gly297Ser; rs9658664) that occurs in a large section of human populations. Association analysis of this single nucleotide polymorphism with cardiovascular/metabolic disease states in Indian populations (n = 4,300 subjects) displays elevated plasma glucose, glycosylated hemoglobin, diastolic blood pressure, and catecholamines in Gly/Ser subjects as compared with wild-type individuals (Gly/Gly). Consistently, the 297Ser allele confers an increased risk (∼1.3-1.6-fold) for type 2 diabetes/hypertension/coronary artery disease/metabolic syndrome. In corroboration, the variant peptide (PST-297S) displays gain-of-potency in several cellular events relevant for cardiometabolic disorders (e.g., increased expression of gluconeogenic genes, increased catecholamine secretion, and greater inhibition of insulin-stimulated glucose uptake) than the wild-type peptide. Computational docking analysis and molecular dynamics simulations show higher affinity binding of PST-297S peptide with glucose-regulated protein 78 (GRP78) and insulin receptor than the wild-type peptide, providing a mechanistic basis for the enhanced activity of the variant peptide. In vitro binding assays validate these in silico predictions of PST peptides binding to GRP78 and insulin receptor. In conclusion, the PST 297Ser allele influences cardiovascular/metabolic phenotypes and emerges as a novel risk factor for type 2 diabetes/hypertension/coronary artery disease in human populations.

Prognostic significance of Troponin I in patients undergoing primary percutaneous coronary intervention

This observational study investigates the prognostic significance of troponin I in patients undergoing primary percutaneous intervention (pPCI). Sequential cardiac biomarker sampling of the enrolled patients (n = 167) was performed on admission and at 6,12,24 and 48 h. Clinical characteristics, major adverse cardiac and cerebrovascular events (MACCE) (death, reinfarction, stroke and new or worsening heart failure) and left ventricular ejection fraction (LVEF) were noted on admission and 30 day follow-up. A 24-h troponin I level >60 ng/ml predicted MACCE (OR 4.06, p = 0.023; adjusted OR 5.09, p = 0.034) and less than 10% improvement in LVEF on follow-up (OR 2.49, p = 0.007). Thus, in patients undergoing pPCI, 24-h cardiac Troponin I is a good non-invasive surrogate to predict MACCE and improvement in LVEF.

Fibrinolytic Strategy for ST-Segment–Elevation Myocardial Infarction

The ongoing coronavirus disease 2019 pandemic has resulted in additional challenges for systems designed to perform expeditious primary percutaneous coronary intervention for patients presenting with ST-segment–elevation myocardial infarction. There are 2 important considerations: the guideline-recommended time goals were difficult to achieve for many patients in high-income countries even before the pandemic, and there is a steep increase in mortality when primary percutaneous coronary intervention cannot be delivered in a timely fashion. Although the use of fibrinolytic therapy has progressively decreased over the last several decades in high-income countries, in circumstances when delays in timely delivery of primary percutaneous coronary intervention are expected, a modern fibrinolytic-based pharmacoinvasive strategy may need to be considered. The purpose of this review is to systematically discuss the contemporary role of an evidence-based fibrinolytic reperfusion strategy as part of a pharmacoinvasive approach, in the context of the emerging coronavirus disease 2019 pandemic.

Validation of a Genome-Wide Polygenic Score for Coronary Artery Disease in South Asians

BACKGROUND

Genome-wide polygenic scores (GPS) integrate information from many common DNA variants into a single number. Because rates of coronary artery disease (CAD) are substantially higher among South Asians, a GPS to identify high-risk individuals may be particularly useful in this population.

OBJECTIVES

This analysis used summary statistics from a prior genome-wide association study to derive a new GPSCAD for South Asians.

METHODS

This GPSCAD was validated in 7,244 South Asian UK Biobank participants and tested in 491 individuals from a case-control study in Bangladesh. Next, a static ancestry and GPSCAD reference distribution was built using whole-genome sequencing from 1,522 Indian individuals, and a framework was tested for projecting individuals onto this static ancestry and GPSCAD reference distribution using 1,800 CAD cases and 1,163 control subjects newly recruited in India.

RESULTS

The GPSCAD, containing 6,630,150 common DNA variants, had an odds ratio (OR) per SD of 1.58 in South Asian UK Biobank participants and 1.60 in the Bangladeshi study (p < 0.001 for each). Next, individuals of the Indian case-control study were projected onto static reference distributions, observing an OR/SD of 1.66 (p < 0.001). Compared with the middle quintile, risk for CAD was most pronounced for those in the top 5% of the GPSCAD distribution-ORs of 4.16, 2.46, and 3.22 in the South Asian UK Biobank, Bangladeshi, and Indian studies, respectively (p < 0.05 for each).

CONCLUSIONS

The new GPSCAD has been developed and tested using 3 distinct South Asian studies, and provides a generalizable framework for ancestry-specific GPS assessment.

A Common Tag Nucleotide Variant in MMP7 Promoter Increases Risk for Hypertension via Enhanced Interactions With CREB (Cyclic AMP Response Element-Binding Protein) Transcription Factor

MMP (matrix metalloproteinase)-7-a potent extracellular matrix degrading enzyme-is emerging as a new regulator of cardiovascular diseases. However, potential contributions of MMP7 genetic variations to hypertension remain unknown. In this study, we probed for the association of a tag single-nucleotide polymorphism in the MMP7 promoter (-181A/G; rs11568818) with hypertension in an urban South Indian population (n=1501). The heterozygous AG genotype significantly increased risk for hypertension as compared with the wild-type AA genotype (odds ratio, 1.60 [95% CI, 1.25-2.06]; P=2.4×10^-4); AG genotype carriers also displayed significantly higher diastolic blood pressure and mean arterial pressure than wild-type AA individuals. The study was replicated in a North Indian population (n=949) (odds ratio, 1.52 [95% CI, 1.11-2.09]; P=0.01). Transient transfection experiments using MMP7 promoter-luciferase reporter constructs revealed that the variant -181G allele conferred greater promoter activity than the -181A allele. Computational prediction and structure-based conformational and molecular dynamics simulation studies suggested higher binding affinity for the CREB (cyclic AMP response element-binding protein) to the -181G promoter. In corroboration, overexpression/downregulation of CREB and chromatin immunoprecipitation experiments provided convincing evidence for stronger binding of CREB with the -181G promoter. The -181G promoter also displayed enhanced responses to hypoxia and epinephrine treatment. The higher promoter activity of -181G allele translated to increased MMP7 protein level, and MMP7-181AG heterozygous individuals displayed elevated plasma MMP7 levels, which positively correlated with blood pressure. In conclusion, the MMP7 A-181G promoter polymorphism increased MMP7 expression under pathophysiological conditions (hypoxic stress and catecholamine excess) via increased interactions with CREB and enhanced the risk for hypertension in its carriers.

Consensus document for invasive coronary physiologic assessment in Asia-Pacific countries

BACKGROUND

Currently, invasive physiologic assessment such as fractional flow reserve is widely used worldwide with different adoption rates around the globe. Patient characteristics and physician preferences often differ in the Asia-Pacific (APAC) region with respect to treatment strategy, techniques, lesion complexity, access to coronary physiology and imaging devices, as well as patient management. Thus, there is a need to construct a consensus document on recommendations for use of physiology-guided percutaneous coronary intervention (PCI) in APAC populations. This document serves as an overview of recommendations describing the best practices for APAC populations to achieve more consistent and optimal clinical outcomes.

METHODS AND RESULTS

A comprehensive multiple-choice questionnaire was provided to 20 interven- tional cardiologists from 10 countries in the APAC region. Clinical evidence, tips and techniques, and clinical situations for the use of physiology-guided PCI in APAC were reviewed and used to propose key recommendations. There are suggestions to continue to develop evidence for lesion and patient types that will benefit from physiology, develop directions for future research in health economics and local data, develop appropriate use criteria in different countries, and emphasize the importance of education of all stakeholders. A consensus recommendation to enhance the penetration of invasive physiology-based therapy was to adopt the 5E approach: Evidence, Education, Expand hardware, Economics and Expert consensus.

CONCLUSIONS

This consensus document and recommendations support interventional fellows and cardiologists, hospital administrators, patients, and medical device companies to build confidence and encourage wider implementation of invasive coronary physiology-guided therapy in the APAC region.

A System of Care for Patients With ST-Segment Elevation Myocardial Infarction in India: The Tamil Nadu-ST-Segment Elevation Myocardial Infarction Program

Importance

Challenges to improving ST-segment elevation myocardial infarction (STEMI) care are formidable in low- to middle-income countries because of several system-level factors.

Objective

To examine access to reperfusion and percutaneous coronary intervention (PCI) during STEMI using a hub-and-spoke model.

Design, Setting, and Participants

This multicenter, prospective, observational study of a quality improvement program studied 2420 patients 20 years or older with symptoms or signs consistent with STEMI at primary care clinics, small hospitals, and PCI hospitals in the southern state of Tamil Nadu in India. Data were collected from the 4 clusters before implementation of the program (preimplementation data). We required a minimum of 12 weeks for the preimplementation data with the period extending from August 7, 2012, through January 5, 2013. The program was then implemented in a sequential manner across the 4 clusters, and data were collected in the same manner (postimplementation data) from June 12, 2013, through June 24, 2014, for a mean 32-week period.

Exposures

Creation of an integrated, regional quality improvement program that linked the 35 spoke health care centers to the 4 large PCI hub hospitals and leveraged recent developments in public health insurance schemes, emergency medical services, and health information technology.

Main Outcomes and Measures

Primary outcomes focused on the proportion of patients undergoing reperfusion, timely reperfusion, and postfibrinolysis angiography and PCI. Secondary outcomes were in-hospital and 1-year mortality.

Results

A total of 2420 patients with STEMI (2034 men [84.0%] and 386 women [16.0%]; mean [SD] age, 54.7 [12.2] years) (898 in the preimplementation phase and 1522 in the postimplementation phase) were enrolled, with 1053 patients (43.5%) from the spoke health care centers. Missing data were common for systolic blood pressure (213 [8.8%]), heart rate (223 [9.2%]), and anterior MI location (279 [11.5%]). Overall reperfusion use and times to reperfusion were similar (795 [88.5%] vs 1372 [90.1%]; P = .21). Coronary angiography (314 [35.0%] vs 925 [60.8%]; P < .001) and PCI (265 [29.5%] vs 707 [46.5%]; P < .001) were more commonly performed during the postimplementation phase. In-hospital mortality was not different (52 [5.8%] vs 85 [5.6%]; P = .83), but 1-year mortality was lower in the postimplementation phase (134 [17.6%] vs 179 [14.2%]; P = .04), and this difference remained consistent after multivariable adjustment (adjusted odds ratio, 0.76; 95% CI, 0.58-0.98; P = .04).

Conclusions and Relevance

A hub-and-spoke model in South India improved STEMI care through greater use of PCI and may improve 1-year mortality. This model may serve as an example for developing STEMI systems of care in other low- to middle-income countries.

The impact of systems-of-care on pharmacoinvasive management with streptokinase: The subgroup analysis of the TN-STEMI programme

Objectives

We evaluated the impact of implementation of the TN-STEMI programme on various characteristics of the pharmacoinvasive group by comparing clinical as well as angiographic outcomes between the pre- and post-implementation groups.

Methods

The TN-STEMI programme involved 2420 patients of which 423 patients had undergone a pharmacoinvasive strategy of reperfusion. Of these, 407 patients had a comprehensive blinded core-lab evaluation of their angiograms post-lysis and clinical evaluation of various parameters including time-delays and adverse cardio- and cerebro-vascular events at 1 year. Streptokinase was used as the thrombolytic agent in 94.6% of the patients.

Results

In the post-implementation phase, there was a significant improvement in ‘First medical contact (FMC)-to-ECG’ (11 vs. 5 min, p < 0.001) and ‘Lysis-to-angiogram’ (98.3 vs. 18.2 h, p < 0.001) times. There was also a significant improvement in the number of coronary angiograms performed within 24 h (20.7% vs. 69.3%, p < 0.001). The ‘Time-to-FMC’ (160 vs. 135 min, p = 0.07) and ‘Total ischemic time’ (210 vs. 176 min, p = 0.22) also showed a decreasing trend. IRA patency rate (70.2% vs. 86%, p < 0.001) and thrombus burden (TIMI grade 0: 49.1% vs. 73.4%, p < 0.001) were superior in this group. The MACCE rates were similar except for fewer readmissions (29.8% vs. 12.6%, p = 0.0002) and target revascularizations at 1 year (4.8% vs. none, p = 0.002) in the post-implementation group.

Conclusion

The implementation of a system-of-care (hub-and-spoke model) in the pharmacoinvasive group of the TN-STEMI programme demonstrated shorter lysis-to-angiogram times, better TIMI flow patterns and lower thrombus burden in the post-implementation phase.

A haplotype variant of the human chromogranin A gene (CHGA) promoter increases CHGA expression and the risk for cardiometabolic disorders

The acidic glycoprotein chromogranin A (CHGA) is co-stored/co-secreted with catecholamines and crucial for secretory vesicle biogenesis in neuronal/neuroendocrine cells. CHGA is dysregulated in several cardiovascular diseases, but the underlying mechanisms are not well established. Here, we sought to identify common polymorphisms in the CHGA promoter and to explore the mechanistic basis of their plausible contribution to regulating CHGA protein levels in circulation. Resequencing of the CHGA promoter in an Indian population (n = 769) yielded nine single-nucleotide polymorphisms (SNPs): G-1106A, A-1018T, T-1014C, T-988G, G-513A, G-462A, T-415C, C-89A, and C-57T. Linkage disequilibrium (LD) analysis indicated strong LD among SNPs at the -1014, -988, -462, and -89 bp positions and between the -1018 and -57 bp positions. Haplotype analysis predicted five major promoter haplotypes that displayed differential promoter activities in neuronal cells; specifically, haplotype 2 (containing variant T alleles at -1018 and -57 bp) exhibited the highest promoter activity. Systematic computational and experimental analyses revealed that transcription factor c-Rel has a role in activating the CHGA promoter haplotype 2 under basal and pathophysiological conditions (viz. inflammation and hypoxia). Consistent with the higher in vitro CHGA promoter activity of haplotype 2, individuals carrying this haplotype had higher plasma CHGA levels, plasma glucose levels, diastolic blood pressure, and body mass index. In conclusion, these results suggest a functional role of the CHGA promoter haplotype 2 (occurring in a large proportion of the world population) in enhancing CHGA expression in haplotype 2 carriers who may be at higher risk for cardiovascular/metabolic disorders.

ENPP1 121Q functional variant enhances susceptibility to coronary artery disease in South Indian patients with type 2 diabetes mellitus

Insulin resistance is associated with endothelial dysfunction and ensuing cardiovascular diseases in type 2 diabetes mellitus (T2DM) patients. ENPP1 is a key modulator of insulin signaling and its polymorphism, K121Q, increases the potency to competitively inhibit insulin receptor binding. We investigated the association of ENPP1 121Q variant with coronary artery disease (CAD) in patients with and without T2DM in South Indian population. Our study was conducted in 913 subjects: 198 patients with CAD, 284 patients in whom T2DM and CAD co-exists, 160 patients with T2DM and no CAD history, and 271 healthy volunteers. Genotyping was performed using PCR-RFLP and PCR-DNA sequencing. Genotype frequency of ENPP1 121Q was higher in disease groups compared to healthy subjects (p < 0.05). T2DM patients who carried polymorphic AC/CC genotypes were at 12.8-fold enhanced risk to CAD (95% CI 4.97-37.18, p < 0.01). Moreover we observed that 121Q, both in heterozygous and homozygous polymorphic states, was a risk factor for CAD without diabetes (OR 4.15, p < 0.01). 121Q variant was associated with T2DM patients with no CAD history too, but the risk was statistically insignificant after multivariate logistic regression analysis (OR 2.32, p > 0.05). We conclude that ENPP1 121Q variant is associated with increased risk for CAD in patients with T2DM in South Indian population. We also report that 121Q variant of ENPP1 was an independent risk factor for CAD irrespective of diabetic milieu. Factors which enhance insulin resistance increase the risk for onset and progression of coronary atherosclerosis irrespective of a diabetic background.

A case of recurrent unstable angina - Insight from optical coherence tomography imaging

Intimal tear is a rare cause of ACS and is angiographically indistinguishable. OCT provides unprecendented insight to the mechanism of ACS with its near tissue level definition. This is a case of unstable angina with non-significant RCA lesion. OCT showed intimal tear/flaps with evidence of thrombi, thus clinching the diagnosis.

Catestatin Gly364Ser Variant Alters Systemic Blood Pressure and the Risk for Hypertension in Human Populations via Endothelial Nitric Oxide Pathway

Catestatin (CST), an endogenous antihypertensive/antiadrenergic peptide, is a novel regulator of cardiovascular physiology. Here, we report case-control studies in 2 geographically/ethnically distinct Indian populations (n≈4000) that showed association of the naturally-occurring human CST-Gly364Ser variant with increased risk for hypertension (age-adjusted odds ratios: 1.483; P=0.009 and 2.951; P=0.005). Consistently, 364Ser allele carriers displayed elevated systolic (up to ≈8 mm Hg; P=0.004) and diastolic (up to ≈6 mm Hg; P=0.001) blood pressure. The variant allele was also found to be in linkage disequilibrium with other functional single-nucleotide polymorphisms in the CHGA promoter and nearby coding region. Functional characterization of the Gly364Ser variant was performed using cellular/molecular biological experiments (viz peptide-receptor binding assays, nitric oxide [NO], phosphorylated extracellular regulated kinase, and phosphorylated endothelial NO synthase estimations) and computational approaches (molecular dynamics simulations for structural analysis of wild-type [CST-WT] and variant [CST-364Ser] peptides and docking of peptide/ligand with β-adrenergic receptors [ADRB1/2]). CST-WT and CST-364Ser peptides differed profoundly in their secondary structures and showed differential interactions with ADRB2; although CST-WT displaced the ligand bound to ADRB2, CST-364Ser failed to do the same. Furthermore, CST-WT significantly inhibited ADRB2-stimulated extracellular regulated kinase activation, suggesting an antagonistic role towards ADRB2 unlike CST-364Ser. Consequently, CST-WT was more potent in NO production in human umbilical vein endothelial cells as compared with CST-364Ser. This NO-producing ability of CST-WT was abrogated by ADRB2 antagonist ICI 118551. In conclusion, CST-364Ser allele enhanced the risk for hypertension in human populations, possibly via diminished endothelial NO production because of altered interactions of CST-364Ser peptide with ADRB2 as compared with CST-WT.

Two-year follow-up data from the STEPP-AMI study: A prospective, observational, multicenter study comparing tenecteplase-facilitated PCI versus primary PCI in Indian patients with STEMI

BACKGROUND

A pharmacoinvasive strategy may alleviate the logistical and geographical barriers in timely reperfusion of ST-segment elevation myocardial infarction (STEMI), especially in a developing country like India.

AIM

To assess the safety and efficacy of pharmacoinvasive strategy versus primary PCI in STEMI patients at 2 years.

METHODS

Patients enrolled in STEPP-AMI, an observational, multicenter, prospective study of 200 patients presenting with STEMI, were followed up for 2 years. Group 'A' comprised of patients with pharmacoinvasive strategy (n=45), and patients who underwent primary PCI (n=155) formed group 'B'. Primary endpoint was composite of death, cardiogenic shock, reinfarction, repeat revascularization of the culprit artery, or congestive heart failure at 30 days, with follow-up till 2 years.

RESULTS

The primary endpoint occurred in 11.1% and 17.8% in group A and in 3.9% and 13.6% in group B, at 30 days and 2 years, respectively (p=0.07, RR=2.87; 95% CI: 0.92-8.97 at 30 days and p=0.47, RR=1.31; 95% CI: 0.62-2.76). There was no difference in bleeding risk between groups, 2.2% in group A and 0.6% in group B ('p'=0.4). The infarct-related artery patency varied at angiogram; it was 82.2% in arm A and 22.6% in arm B ('p'<0.001). In group A, failed fibrinolysis occurred in 12.1%.

CONCLUSION

A pharmacoinvasive strategy resulted in outcomes that were comparable with primary PCI at 2 years, suggesting it might be a viable option in India. Larger studies are required to confirm these findings.

Paclitaxel-Eluting versus Everolimus-Eluting Coronary Stents in Diabetes

BACKGROUND

The choice of drug-eluting stent in the treatment of patients with diabetes mellitus and coronary artery disease who are undergoing percutaneous coronary intervention (PCI) has been debated. Previous studies comparing paclitaxel-eluting stents with stents eluting rapamycin (now called sirolimus) or its analogues (everolimus or zotarolimus) have produced contradictory results, ranging from equivalence between stent types to superiority of everolimus-eluting stents.

METHODS

We randomly assigned 1830 patients with diabetes mellitus and coronary artery disease who were undergoing PCI to receive either a paclitaxel-eluting stent or an everolimus-eluting stent. We used a noninferiority trial design with a noninferiority margin of 4 percentage points for the upper boundary of the 95% confidence interval of the risk difference. The primary end point was target-vessel failure, which was defined as a composite of cardiac death, target-vessel myocardial infarction, or ischemia-driven target-vessel revascularization at the 1-year follow-up.

RESULTS

At 1 year, paclitaxel-eluting stents did not meet the criterion for noninferiority to everolimus-eluting stents with respect to the primary end point (rate of target-vessel failure, 5.6% vs. 2.9%; risk difference, 2.7 percentage points [95% confidence interval, 0.8 to 4.5]; relative risk, 1.89 [95% confidence interval, 1.20 to 2.99]; P=0.38 for noninferiority). There was a significantly higher 1-year rate in the paclitaxel-eluting stent group than in the everolimus-eluting stent group of target-vessel failure (P=0.005), spontaneous myocardial infarction (3.2% vs. 1.2%, P=0.004), stent thrombosis (2.1% vs. 0.4%, P=0.002), target-vessel revascularization (3.4% vs. 1.2%, P=0.002), and target-lesion revascularization (3.4% vs. 1.2%, P=0.002).

CONCLUSIONS

In patients with diabetes mellitus and coronary artery disease undergoing PCI, paclitaxel-eluting stents were not shown to be noninferior to everolimus-eluting stents, and they resulted in higher rates of target-vessel failure, myocardial infarction, stent thrombosis, and target-vessel revascularization at 1 year. (Funded by Boston Scientific; TUXEDO-India Clinical Trials Registry-India number, CTRI/2011/06/001830).

Framework for a National STEMI Program: consensus document developed by STEMI INDIA, Cardiological Society of India and Association Physicians of India

The health care burden of ST elevation myocardial infarction (STEMI) in India is enormous. Yet, many patients with STEMI can seldom avail timely and evidence based reperfusion treatments. This gap in care is a result of financial barriers, limited healthcare infrastructure, poor knowledge and accessibility of acute medical services for a majority of the population. Addressing some of these issues, STEMI India, a not-for-profit organization, Cardiological Society of India (CSI) and Association Physicians of India (API) have developed a protocol of "systems of care" for efficient management of STEMI, with integrated networks of facilities. Leveraging newly-developed ambulance and emergency medical services, incorporating recent state insurance schemes for vulnerable populations to broaden access, and combining innovative, "state-of-the-art" information technology platforms with existing hospital infrastructure, are the crucial aspects of this system. A pilot program was successfully employed in the state of Tamilnadu. The purpose of this article is to describe the framework and methods associated with this programme with an aim to improve delivery of reperfusion therapy for STEMI in India. This programme can serve as model STEMI systems of care for other low-and-middle income countries.

Risk scoring system to predict contrast induced nephropathy following percutaneous coronary intervention

BACKGROUND

Contrast induced nephropathy (CIN) is associated with significant morbidity and mortality after percutaneous coronary intervention (PCI). The aim of this study is to evaluate the collective probability of CIN in Indian population by developing a scoring system of several identified risk factors in patients undergoing PCI.

METHODS

This is a prospective single center study of 1200 consecutive patients who underwent PCI from 2008 to 2011. Patients were randomized in 3:1 ratio into development (n = 900) and validation (n = 300) groups. CIN was defined as an increase of ≥25% and/or ≥0.5 mg/dl in serum creatinine at 48 hours after PCI when compared to baseline value. Seven independent predictors of CIN were identified using logistic regression analysis - amount of contrast, diabetes with microangiopathy, hypotension, peripheral vascular disease, albuminuria, glomerular filtration rate (GFR) and anemia. A formula was then developed to identify the probability of CIN using the logistic regression equation.

RESULTS

The mean (±SD) age was 57.3 (±10.2) years. 83.6% were males. The total incidence of CIN was 9.7% in the development group. The total risk of renal replacement therapy in the study group is 1.1%. Mortality is 0.5%. The risk scoring model correlated well in the validation group (incidence of CIN was 8.7%, sensitivity 92.3%, specificity 82.1%, c statistic 0.95).

CONCLUSION

A simple risk scoring equation can be employed to predict the probability of CIN following PCI, applying it to each individual. More vigilant preventive measures can be applied to the high risk candidates.

A prospective, observational, multicentre study comparing tenecteplase facilitated PCI versus primary PCI in Indian patients with STEMI (STEPP-AMI)

Objective

To compare the efficacy of pharmacoinvasive strategy versus primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI). Primary PCI is the preferred treatment for STEMI, but it is not a feasible option for many. A pharmacoinvasive strategy might be a practical solution in the Indian context, although few empirical data exist to guide this approach.

Methods

This is a prospective, observational, multicentre pilot study. Two hundred consecutive patients with STEMI aged 18–75 years, presenting within 12 h of onset of symptoms and requiring a reperfusion strategy, were studied from five primary PCI capable centres in South India. Patients who opted for pharmacoinvasive strategy (n=45) formed group A. Group B consisted of patients treated with primary PCI (n=155). One patient was lost to follow-up at 1 year. The primary end point was a composite of death, cardiogenic shock, reinfarction, repeat revascularisation of a culprit artery and congestive heart failure at 30 days.

Results

The primary end point occurred in 11.1% in group A and in 3.9% in group B, p=0.07 (RR=2.87; 95% CI 0.92 to 8.97). The infarct-related artery patency at angiogram was 82.2% in group A and 22.6% in group B (p<0.001). PCI was performed in 73.3% in group A versus 100% in group B (p<0.001), and a thrombus was present in 26.7% in group A versus 63.2% in group B (p<0.001). Failed fibrinolysis occurred in 12.1% in group A. There was no difference in bleeding risk, 2.2% in group A versus 0.6% in group B, (p=0.4).

Conclusions

This pilot study shows that a pharmacoinvasive strategy can be implemented in patients not selected for primary PCI in India and hints at the possibility of similar outcomes. Larger studies are required to confirm these findings.

Trial registration number

Trial is registered with Clinical trial registry of India, CTRI number: REF/2011/07/002556.

A prospective, randomized study to evaluate the efficacy of various diuretic strategies in acute decompensated heart failure

AIM

To evaluate the safety and efficacy of various initial strategies of loop diuretic administration in patients with acute decompensated heart failure (ADHF) on diuresis, renal function, electrolyte balance and clinical outcomes.

METHODS

Consecutive patients admitted with ADHF were randomized into three groups - intravenous furosemide infusion + intravenous dopamine, intravenous furosemide bolus in two divided doses and intravenous furosemide continuous infusion alone. At 48 h, the treating physician could adjust the diuretic strategy. Primary endpoint was negative fluid balance at 24 h after admission. Secondary end points were duration of hospital stay, negative fluid balance at 48, 72, 96 h, the trend of serum electrolytes, and renal function and 30 day clinical outcome (death and emergency department visits).

RESULTS

Overall ninety patients (thirty in each group) were included in the study. There was a greater diuresis in first 24 h (p = 0.002) and a shorter hospital stay (p = 0.023) with the bolus group. There was no significant difference in renal function and serum sodium and serum potassium levels. There was no difference in the number of emergency department visits among the three groups.

CONCLUSION

All three modes of diuretic therapies can be practiced with no difference in worsening of renal function and electrolyte levels. Bolus dose administration with its rapid volume loss and shorter hospital stay might be a more effective diuretic strategy.

Three-year data from the XIENCE V INDIA study: safety and efficacy of XIENCE V in 1000 real world Indian patients

BACKGROUND

Cardiovascular disease in Asia has reached epidemic proportions in recent years. Use of drug eluting stents in Asians has rapidly expanded with varying penetration rates across different countries. The XIENCE V INDIA Study included 'real world' patients who underwent XIENCE V stent implantation to assess short and intermediate term outcomes in Indian patients with diverse risk factors.

OBJECTIVE

To evaluate 3-year clinical outcomes in a cohort of 'real world' Indian patients with CAD being treated with XIENCE V Everolimus Eluting Coronary Stent System.

METHODS

1000 patients were enrolled from 18 sites in India between June 2008 and March 2009. Patients were included if their index procedures were completed using only XIENCE V. There were no clinical or angiographic exclusions. An independent Clinical Events Committee adjudicated all endpoint-related events. The primary endpoint was stent thrombosis rate annually through to 3 years as defined by the Academic Research Consortium criteria. The co-primary endpoint was the composite rate of cardiac death and myocardial infarction at 1 year.

RESULTS

At 1-year the primary endpoint of definite/probable stent thrombosis rate was 0.51%. No additional very late stent thrombosis was reported through a 3-year follow up. The composite endpoint of cardiac death and any myocardial infarction was 1.9%, 2.7% and 3.1% at 1, 2 and 3 years respectively.

CONCLUSION

Despite the high risk population of coronary artery disease, the use of XIENCE V in 'real world' Indian patients was associated with very low clinical event rates upto three years of follow up.

Naturally occurring variants of the dysglycemic peptide pancreastatin: differential potencies for multiple cellular functions and structure-function correlation

Pancreastatin (PST), a chromogranin A-derived peptide, is a potent physiological inhibitor of glucose-induced insulin secretion. PST also triggers glycogenolysis in liver and reduces glucose uptake in adipocytes and hepatocytes. Here, we probed for genetic variations in PST sequence and identified two variants within its functionally important carboxyl terminus domain: E287K and G297S. To understand functional implications of these amino acid substitutions, we tested the effects of wild-type (PST-WT), PST-287K, and PST-297S peptides on various cellular processes/events. The rank order of efficacy to inhibit insulin-stimulated glucose uptake was: PST-297S > PST-287K > PST-WT. The PST peptides also displayed the same order of efficacy for enhancing intracellular nitric oxide and Ca(2+) levels in various cell types. In addition, PST peptides activated gluconeogenic genes in the following order: PST-297S ≈ PST-287K > PST-WT. Consistent with these in vitro results, the common PST variant allele Ser-297 was associated with significantly higher (by ∼17 mg/dl, as compared with the wild-type Gly-297 allele) plasma glucose level in our study population (n = 410). Molecular modeling and molecular dynamics simulations predicted the following rank order of α-helical content: PST-297S > PST-287K > PST-WT. Corroboratively, circular dichroism analysis of PST peptides revealed significant differences in global structures (e.g. the order of propensity to form α-helix was: PST-297S ≈ PST-287K > PST-WT). This study provides a molecular basis for enhanced potencies/efficacies of human PST variants (likely to occur in ∼300 million people worldwide) and has quantitative implications for inter-individual variations in glucose/insulin homeostasis.

Protocol for a prospective, controlled study of assertive and timely reperfusion for patients with ST-segment elevation myocardial infarction in Tamil Nadu: the TN-STEMI programme

INTRODUCTION

Over the past two decades, India has witnessed a staggering increase in the incidence and mortality of ST-elevation myocardial infarction (STEMI). Indians have higher rates of STEMI and younger populations that suffer from it when compared with developed countries. Yet, the recommended reperfusion therapy with fibrinolysis and percutaneous coronary intervention is available only to a minority of patients. This gap in care is a result of financial barriers, limited healthcare infrastructure and poor knowledge and accessibility of acute medical services for a majority of its population.

METHODS AND ANALYSIS

This is a prospective, multicentre, 'pretest/post-test' quasi-experimental, community-based study. This programme will use a 'hub-and-spoke' model of an integrated healthcare network based on clusters of primary-care health clinics, small hospitals and large tertiary-care facilities. It is an 'all-comers' study which will enrol consecutive patients presenting with STEMI to the participating hospitals. The primary objectives of the study is to improve the use of reperfusion therapy and reduce the time from first medical contact to device or drug in STEMI patients; and to increase the rates of early invasive risk stratification with coronary angiography within 3-24 h of fibrinolytic therapy in eligible patients through changes in process of care. Outcomes will be measured with statistical comparison made before and after implementing the TN-STEMI programme. The estimated sample size is based on the Kovai Erode Pilot study, which provided an initial work on establishing this type of programme in South India. It will be adequately powered at 80% with a superiority margin of 10% if 36 patients are enrolled per cluster or 108 patients in three clusters. Thus, the enrolment period of 9 months will result in a sample size of 1500 patients.

ETHICS

This study will be conducted in accordance with the ethical principles that have their origin in the current Declaration of Helsinki and 'ethical guidelines for biomedical research on human participants' as laid down by the Indian Council for Medical Research. All participating hospitals will still obtain local ethics committee approval of the study protocol and written informed consent will be obtained from all participants.

DISSEMINATION AND RESULTS

Our findings will be reported through scientific publications, research conferences and public policy venues aimed at state and local governments in India. If successful, this model can be extended to other areas of India as well as serve as a model of STEMI systems of care for low-income and middle-income countries across the world.

REGISTRATION

Trial is registered with Clinical trial registry of India, No: CTRI/2012/09/003002.

Functional genetic variants of the catecholamine-release-inhibitory peptide catestatin in an Indian population: allele-specific effects on metabolic traits

Catestatin (CST), a chromogranin A (CHGA)-derived peptide, is a potent inhibitor of catecholamine release from adrenal chromaffin cells and postganglionic sympathetic axons. We re-sequenced the CST region of CHGA in an Indian population (n = 1010) and detected two amino acid substitution variants: G364S and G367V. Synthesized CST variant peptides (viz. CST-Ser-364 and CST-Val-367) were significantly less potent than the wild type peptide (CST-WT) to inhibit nicotine-stimulated catecholamine secretion from PC12 cells. Consistently, the rank-order of blockade of nicotinic acetylcholine receptor (nAChR)-stimulated inward current and intracellular Ca(2+) rise by these peptides in PC12 cells was: CST-WT > CST-Ser-364 > CST-Val-367. Structural analysis by CD spectroscopy coupled with molecular dynamics simulations revealed the following order of α-helical content: CST-WT > CST-Ser-364 > CST-Val-367; docking of CST peptides onto a major human nAChR subtype and molecular dynamics simulations also predicted the above rank order for their binding affinity with nAChR and the extent of occlusion of the receptor pore, providing a mechanistic basis for differential potencies. The G364S polymorphism was in strong linkage disequilibrium with several common CHGA genetic variations. Interestingly, the Ser-364 allele (detected in ∼15% subjects) was strongly associated with profound reduction (up to ∼2.1-fold) in plasma norepinephrine/epinephrine levels consistent with the diminished nAChR desensitization-blocking effect of CST-Ser-364 as compared with CST-WT. Additionally, the Ser-364 allele showed strong associations with elevated levels of plasma triglyceride and glucose levels. In conclusion, a common CHGA variant in an Indian population influences several biochemical parameters relevant to cardiovascular/metabolic disorders.

Pharmacoinvasive Management

The goal of treatment of patients with ST-segment elevation myocardial infarction (STEMI) is timely restoration of myocardial blood flow. Primary percutaneous coronary intervention (PCI) remains the treatment of choice for STEMI patients, as shown in multiple clinical trials. However, because of logistic constraints, timely primary PCI may not be possible for many STEMI patients, most of whom are treated with fibrinolysis. Debate continues as to whether, and when, patients treated with fibrinolysis should undergo subsequent PCI. Current data support the strategy of early routine PCI after fibrinolysis rather than the conservative standard-care approach or rescue PCI for failed lysis.

Door-to-balloon: where do we lose time? Single centre experience in India

BACKGROUND/AIMS

To assess the factors causing delay in attaining DTB time of <90 min.

METHODS

Eighty-five patients who underwent primary PCI from August 2008 to July 2009 were studied. From door-to-balloon, time was divided into 6 stages; any reason for delay was studied.

RESULTS

The mean DTB time was 80.5 min (SD = 34.4, median time 75 min, range 30-195). DTB time was <90 min in 76.5%, and DTB time >90 min occurred in 23.5%. Mean door to ECG - 6.5 min (SD = 2.7), mean time for the decision of PCI - 7.5 min (SD = 10.5), mean time taken for the patient's consent - 19.6 min (SD = 17.6), for STEMI team activation - 6.7 min (SD = 7.6), average time for financial process - 39.2 min (SD = 22.9). Average time for sheath to balloon - 5.2 min (SD = 1.7). Hospital related delay occurred in 5%, patient related delay in 80%, both together in 15%. 89.5% of patient related delay was due to delay in giving consent and financial reasons. There was no statistically significant delay for patients presented at morning or night and during the weekdays or weekend. Total mortality was 4.7%. Mortality among <90 min was 3.1%, mortality among >90 min was 10% ('p' = 0.2).

CONCLUSIONS

With effective hospital strategies, the DTB time of 90 min can be achieved in majority of patients. The chief delay in DTB time in this study was due to a delay in obtaining consent and financial reasons.

Longitudinal deformation - price we pay for better deliverability of coronary stent platforms

Coronary stents, especially drug eluting stents (DES), have revolutionized the practice of interventional cardiology. Newer stents are manufactured by altering basic design characteristics to tackle complex coronary morphologies more effectively. Alteration in one particular attribute might affect other attributes adversely. Even though, reduction in the number and alteration of the orientation of the connectors improves the stent flexibility and deliverability, it adversely decreases the axial strength of the stent with resulting longitudinal stent deformation. A 67 year old female underwent percutaneous coronary intervention for a mid left anterior descending artery stenosis with a 2.75 × 16 mm Promus Element stent (Boston Scientific, Natick, Massachusetts). The stent got longitudinally distorted during post-stent balloon dilatation which was effectively managed with further dilatation with non-compliant balloon.

Managing complications in acute myocardial infarction

Acute myocardial infarction (AMI) due to coronary artery disease is a leading cause of death in both the developed and developing countries. The advent of coronary care units and early reperfusion therapy (Thrombolytic and Percutaneous Coronary Intervention) has substantially decreased in-hospital mortality rates and has improved the outcome in survivors of the acute phase of MI. Complications of AMI include mechanical, arrhythmic, ischemic, and inflammatory (early pericarditis and post-MI syndrome) sequelae, as well as left ventricular mural thrombus. In addition to these broad categories, right ventricular (RV) infarction and cardiogenic shock are other common complications of AMI. The onset of each of these complications usually results in explicit symptoms and physical manifestations. Thus, a basic knowledge of the complications that occur in the postinfarction period and the clinical syndromes associated with each, will allow the physician to evaluate and treat the complication appropriately.

Evaluation of the XIENCE V everolimus eluting coronary stent system in the Asian population of the SPIRIT V single arm study. 2-year clinical follow-up data

BACKGROUND

Asian patients have a uniquely high risk for heart disease compared to other ethnicities. Past drug eluting stent trials have examined mainly populations of European heritage. As a significant proportion of the real world population in the SPIRIT V single arm study is Asian, the study provides insight into how this population responds to stenting with the XIENCE V Everolimus Eluting Coronary Stent (EES).

METHODS AND RESULTS

2,700 patients were enrolled at 93 sites in Europe, Asia Pacific and Canada between November 2006 and November 2007. 698 (26%) patients were recruited from Asian sites in India, China, Hong Kong, Malaysia, Singapore and Thailand. De novo coronary artery lesions of all patients were to be treated with up to 4 planned EES. Up to 2 year follow-up, major adverse cardiac events, myocardial infarction and target lesion revascularization rates were lower in the Asian subgroup than in the non-Asian subgroup. These results were mainly driven by better clinical outcomes in the Indian population. All populations showed similar low stent thrombosis rates.

CONCLUSION

These findings demonstrate the safety and efficacy of the EES when used in a real-world Asian population, known to be at higher risk for heart disease.

The SPIRIT V study: a clinical evaluation of the XIENCE V everolimus-eluting coronary stent system in the treatment of patients with de novo coronary artery lesions

OBJECTIVES

The SPIRIT V (A Clinical Evaluation of the XIENCE V Everolimus-Eluting Coronary Stent System in the Treatment of Patients With De Novo Coronary Artery Lesions) study is a post-market surveillance experience of the XIENCE V (Abbott Vascular, Santa Clara, California) everolimus-eluting stent (EES) in patients with higher-risk coronary anatomy.

BACKGROUND

Previous pre-approval studies have shown the safety and efficacy of EES in highly selected groups of patients.

METHODS

The SPIRIT V trial is a prospective, open label, single arm, multicenter study. Two thousand seven hundred patients with multiple de novo coronary artery lesions suitable for treatment with a planned maximum of 4 EES were enrolled at 93 centers in Europe, Asia Pacific, Canada, and South Africa. Lesions had a reference vessel diameter between 2.25 and 4.0 mm and a length of ≤ 28 mm by visual estimation. An independent clinical events committee adjudicated all end point-related events. The primary end point was the composite rate of all death, myocardial infarction (MI), and target vessel revascularization at 30 days. Secondary end points included stent thrombosis and acute success (clinical device and procedure success).

RESULTS

At 30 days, the primary composite end point of all death, MI, and target vessel revascularization was 2.7%. At 1 year, rates of cardiac death, overall MI, and target lesion revascularization were 1.1%, 3.5%, and 1.8%, respectively. The cumulative rate of definite and probable stent thrombosis was low at 0.66% at 1 year.

CONCLUSIONS

Use of EES in patients with multiple, complex de novo lesions yielded 1-year major adverse cardiac events, stent thrombosis, and target lesion revascularization rates that are comparable to those of the more controlled SPIRIT II and SPIRIT III trials-which included patients with restricted inclusion/exclusion criteria-and other all-comer population, physician-initiated studies like the X-SEARCH (Xience Stent Evaluated At Rotterdam Cardiology Hospital) and COMPARE (A Randomized Controlled Trial of Everolimus-eluting Stents and Paclitaxel-eluting Stents for Coronary Revascularization in Daily Practice) trials.

Successful hybrid procedure in flash pulmonary edema

A 70-year-old lady with recurrent flash pulmonary edema and acute coronary syndrome was detected to have bilateral renal artery disease and uncontrolled hypertension. Her right kidney size was 9.3 Χ 3.2 cm [glomerular filtration rate (GFR) 32.65 mL/min], left kidney size was 6.8 Χ 2.9 cm (GFR 12.78 mL/min), with a total GFR of 45.43 mL/min. Angiogram showed significant bilateral atherosclerotic renal artery stenosis and 90% right coronary artery lesion. She underwent successful percutaneous transluminal angioplasty of right renal artery lesion. Her serum creatinine of 1.6 mg/dL (GFR 45.43 mL/min) came down to 1.3 mg/dL (GFR 63 mL/min) post procedure and her blood pressure was controlled. She then underwent percutaneous transluminal coronary angioplasty of right coronary artery lesion. Renal artery stenosis is an important cause of uncontrolled hypertension and progression to chronic kidney disease. An early intervention and prompt revascularization prevents recurrent flash pulmonary edema and end stage kidney failure.

Influence of intrinsic myocardial conduction on paced QRS morphology during cardiac resynchronization therapy follow up

We report two cases of patients of cardiac resynchronization therapy (CRT) whose ECGs, during follow up, showed different paced QRS morphology as compared to those of immediate post-device implantation. Parameters of leads, including sensitivity and capture thresholds, were unchanged. There was no lead dislodgement confirmed on fluoroscopy. The ECGs obtained in device off mode showed different intrinsic QRS morphology as compared to those of pre-implant morphology. These changes were attributable to electrolyte imbalance in one patient and progressive intraventricular conduction defect in the other. These cases demonstrate that intrinsic myocardial conduction pattern influences paced QRS morphology. Irreversible change in paced QRS morphology may indicate poor prognosis.

Accuracy of 64-slice coronary CT angiography in predicting percentage diameter stenosis

OBJECTIVE

Aim of our study was to evaluate the diagnostic accuracy of 64-slice CT coronary angiogram in measuring the percentage diameter stenosis compared to invasive angiography.

METHODS AND RESULTS

100 consecutive patients with more than 50% stenosis in at least one major coronary artery measured by 64-slice CT angiogram were included in the study. Patients with atrial fibrillation, history of allergy to contrast agent, acute coronary syndrome, renal insufficiency, history of previous coronary bypass surgery or percutaneous transluminal coronary stent, heart rate more than 70 per minute at the time of scan in spite of beta-blocker therapy, and calcium score >2000 Agaston units were not included in the study. 15-segment American Heart Association classification was used, and segments were compared using qualitative angiography. 192 segments (12.80%) could not be assessed due to poor image quality. The major cause for poor image quality was dense calcification precluding the luminal assessment (60.42%). Comparing the maximal percentage diameter stenosis by 64-slice CT versus invasive angiogram, the Spearman correlation coefficient between the two modalities was 0.788 and p value was <0.001. Bland-Altman analysis showed a mean difference in percentage stenosis of 2.1 +/- 16.22%. A total of 91.97% (401 of 436) of segments were within 1.96 standard deviations.

CONCLUSION

This study shows that 64-slice CT coronary angiogram is accurate in detecting percentage diameter stenosis compared to coronary angiogram if the image quality is good. Calcifications and motion artifacts are the main culprits of poor image quality.

Outcomes of carotid artery stenting in patients with symptomatic and asymptomatic carotid artery stenosis

OBJECTIVE

Carotid endarterectomy is superior to medical therapy in patients with significant extracranial carotid artery stenosis. This modality of treatment has its own complications. The principal objective of this study is to assess efficacy, feasibility and outcomes of carotid artery stenting in both symptomatic and asymptomatic carotid artery stenosis.

METHODS

Our study is a retrospective analysis of 45 consecutive patients with 56 lesions who underwent carotid angioplasty with stenting from January 2000 to June 2007 for carotid artery stenosis of more than 70%. All patients underwent detailed neurological examination and carotid Doppler evaluation by using Sonos 5500. Computed tomography of brain was done in those patients who were symptomatic in the past.

RESULTS

The mean age of the study population was 65 +/- 9.2 years. There were 34 (79%) patients with coronary artery disease and out of them 31 (68%) patients had undergone coronary artery bypass grafting. All patients with common carotid artery, 13 (81%) patients with right internal carotid stenosis and 12 (66%) patients with left internal carotid artery stenosis had ostioproximal stenosis. Contralateral lesion was found in 9 patients and 2 patients had total occlusion. There were no post-procedural neurological events. Only one patient died in our study population due to non-cerebral cause.

CONCLUSION

Carotid artery stenting is a safe procedure. The 30 days' outcomes are similar in both symptomatic and asymptomatic patients with significant carotid artery stenosis.

High intensity exercise training programme following cardiac transplant

A 26-year-old male patient who presented with symptoms of end stage cardiac failure as a result of dilated cardiomyopathy, had an orthotopic cardiac transplantation. A comprehensive cardiac rehabilitation programme was provided to him and he was introduced to a sport (tennis). The exercise training programme progressed from low intensity training to high intensity programme over a period of 15 months. A cardio-pulmonary exercise test done 22 months after surgery suggested that he was able to achieve the aerobic capacity comparable to that of a normal South Indian subject. He participated successfully in the World Transplant Games in Sydney and returned safely. This suggests that after a proper cardiac rehabilitation programme, patients undergoing heart transplantation can achieve normal physiological responses to lead a normal active life.

Carotid artery stenting prior to coronary artery bypass graft surgery inpatients with left-main-coronary-artery disease

Patients with concomitant carotid and left main or left main equivalent coronary artery disease are at high risk of both cardiac and cerebrovascular complications when they undergo revascularization procedures. Here, we present case reports of three patients who successfully underwent elective carotid stenting prior to coronary artery bypass surgery. Any sort of intervention in these patients is fraught with high risk due to the severity of their carotid and coronary artery disease.

Long-term results of radiofrequency ablation of slow pathway in patients with atrioventricular nodal reentrant tachycardia: single-center experience

BACKGROUND

This study sought to evaluate the long-term recurrence rate of atrioventricular nodal reentrant tachycardia (AVNRT) after radiofrequency catheter ablation. The clinical and electrophysiological features of patients with AVNRT and their immediate outcomes after undergoing slow pathway ablation/modification were also studied.

METHODS AND RESULTS

The study included 264 consecutive patients with AVNRT (mean age 46 -/+ 15 years, 143 women, 121 men) who underwent slow pathway ablation/modification using a combined electrophysiological and anatomical approach. The primary endpoint of ablation procedure was non- inducibility of the arrhythmia. The primary endpoint of the study was the recurrence of AVNRT on follow-up. Acute success was achieved in 262 (99.6%) patients. Complication rate of the ablation procedure was 2.6% and the average fluoroscopy time was 18.3 -/+ 11 minutes. The patients were followed up for a mean duration of 20 -/+ 9 months during which there was only one case of recurrence.

CONCLUSION

Radiofrequency ablation or modification of slow pathway is highly effective in the treatment of AVNRT. The technique has a high initial success rate and a low complication rate. The recurrence rates are extremely low (0.3%) on long-term follow-up.

A case of lipomatous hypertrophy of right ventricle

Lipomatous hypertrophy is a condition that is being increasingly diagnosed with the advent of newer modalities. A middle aged lady was referred to us with recent onset dyspnea and palpitations. Echocardiography revealed diffuse thickening of the right ventricular free wall and outflow tract. Endomyocardial biopsy revealed this as a lipomatous hypertrophy involving the right ventricle. This is the first reported case of lipomatous hypertrophy involving the right ventricle.

Elective stenting in superior vena cava syndrome caused by idiopathic fibrosing mediastinitis: use of self-expandable wallstent

We present a case of superior vena cava obstruction caused by idiopathic fibrosing mediastinitis treated with a self-expandable Wallstent. A Gortex jump graft had been used previously, which was totally occluded. This procedure relieved symptoms and alleviated the need for re-operation.

Iliac artery stenosis causing post-renal transplant hypertension: successful management by percutaneous angioplasty and stent implantation

Atherosclerotic occlusion of the native iliac arteries and/or transplant renal artery is a major cause of post-transplant hypertension. Iliac artery stenosis mimics renovascular hypertension and may cause renal dysfunction in transplant recipients. We report a case of a 61-year-old renal transplant recipient with native bilateral iliac artery stenoses and coronary artery disease. He presented with severe hypertension and was managed successfully with angioplasty and stenting of native iliac arteries.