Viji Samuel Thomson

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.

Externalized Guidewires to Facilitate Fenestrated Endograft Deployment in the Aortic Arch

Purpose: To describe a precannulated fenestrated endograft system utilizing externalized guidewires to facilitate aortic arch endovascular repair and to report its use in 2 patients with challenging anatomy. Technique: For distal arch repair, a fenestration for the left subclavian artery (LSA) is made onsite in a standard thoracic endograft tailored to the patient anatomy; it is precannulated with a nitinol guidewire (NGw), which is passed from the femoral artery and externalized from the left brachial artery prior to endograft delivery system introduction over a parallel stiff guidewire. Steps are then taken to remove guidewire intertwining, prevent NGw wrapping around the delivery system, and orient the LSA fenestration superiorly when the delivery system moves into the arch. Gentle traction on the ends of the NGw during endograft deployment facilitates proper fenestration alignment. A covered stent is deployed in the LSA fenestration. The technique is illustrated in a patient with congenital coarctation of the aorta and descending aortic aneurysm. For total arch repair, endograft fenestrations are made for all 3 arch branches; the left common carotid artery (LCCA) and LSA fenestrations are each cannulated with NGws, which travel together from the femoral artery, pass through a LSA snare loop, and are exteriorized from the LCCA. After endograft deployment, the innominate artery fenestration is separately cannulated using right brachial access. Placement of a parallel externalized hydrophilic guidewire passing through the LCCA fenestration (but not the LSA snare loop) and removal of the LCCA fenestration NGw allows exteriorization of the LSA fenestration NGw from the left brachial artery by pulling the LSA snare. Covered stents are deployed in all 3 fenestrations. The technique is presented in a patient with type B aortic dissection. Conclusion: Use of the precannulated fenestrated endograft system described is feasible and has the potential to make aortic arch endovascular repair simpler, more reliable, and safer.

Aspirin resistance in Indian patients with coronary artery disease and cardiovascular events.

BACKGROUND Aspirin resistance is a major problem and its incidence and clinical significance in Indian patients with documented coronary artery disease are not known. AIM We sought to study the incidence of aspirin resistance and its clinical significance in a cohort of Indian patients with coronary heart disease on therapy with aspirin using urinary 11-Dehydrothromboxane B2 levels as a surrogate marker for antiplatelet efficacy. SETTING AND DESIGN Non randomized single center prospective study in cohort of patients with stable cardiovascular disease on chronic aspirin therapy attending the cardiology outpatient clinic of a tertiary care hospital. MATERIALS AND METHODS Urinary dehydrothromboxane levels were analyzed in a cohort of 63 patients with stable documented coronary artery disease and in 21 healthy volunteers. The cases were followed up prospectively for a median period of 36 (1-53) months. The clinical endpoint was a composite of acute coronary syndrome, stroke, revascularization and death. STATISTICAL ANALYSIS Comparison of urinary dehydrothromboxane concentration values between various risk factors was done using Mann Whitney U test, a non parametric alternative of independent t test. All statistical analyses were done using SPSS 11.0 (Chicago, USA) software. RESULTS The median (range) absolute values of urinary11- dehydrothromboxane B2 levels for the healthy volunteers and cases were 440 (286-2050) pg/ml and 320 (72-2600) pg/ml (P=0.007). The corresponding normalized values were 87.3 (43-143) and 60.8 (16.7-943) ng/mmol of creatinine (P=0.131). Among the various vascular risk factors, patients who were overweight had higher absolute levels of 11- urinary dehydrothomboxane B2 levels (P=0.016). There were significantly more clinical events in patients with absolute urinary 11-dehydrothromboxane B2 levels in the upper two quartiles compared to the lower two quartiles (P=0.04). CONCLUSION The incidence of aspirin resistance in the cohort of patients with documented heart disease was 38.1%. Patients with elevated absolute urinary dehydrothomboxane levels (>320 pg/ml) on chronic aspirin therapy constitute a high risk subset for recurrent vascular events.

Corsair microcatheter for retrograde coronary chronic total occlusion recanalization: early experience outside the realm of dedicated recanalization specialists.

OBJECTIVE To determine the extent to which use of the Corsair microcatheter (CM, Asahi Intecc Co., Japan) improves procedural outcomes when an experienced operator who is not a dedicated recanalization specialist attempts retrograde chronic total occlusion (CTO) recanalization through collateral channels during percutaneous coronary intervention. BACKGROUND The recently introduced CM has improved success rates of retrograde CTO recanalization to nearly 100% in the hands of dedicated coronary recanalization specialists; however, the impact the CM has on the results of non-specialist operators attempting retrograde CTO recanalization is not known. METHODS A non-specialist operator attempted CM-assisted recanalization in seven consecutive CTO cases requiring retrograde recanalization. The results obtained were compared with those achieved by the same operator in eleven consecutive retrograde CTO recanalization procedures during the last 2 years before the CM became available. RESULTS CM-assisted retrograde CTO recanalization was successful in 6 of 7 cases (86%), but failed in one case attempted through a tortuous epicardial collateral; there were no complications. In contrast, during the 2 years before the CM became available, retrograde CTO recanalization was successful in only 3 of 11 attempted cases (27%), and was associated with significant morbidity. Lesions in the two groups were comparable in terms of technical difficulty and procedural risk. CONCLUSIONS The non-specialist operators retrograde CTO recanalization results improve significantly when using the CM. Given the effectiveness and safety of CM-assisted retrograde CTO recanalization, operators should be less aggressive with anterograde recanalization attempts, and should switch to the retrograde approach earlier and more often.

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.

Assessment of left ventricular systolic function by velocity vector imaging.

OBJECTIVES To study the usefulness of a novel echocardiographic technique, velocity vector imaging (VVI) in the measurement of left ventricular ejection fraction (LVEF). BACKGROUND Ejection fraction measured by echocardiography forms the cornerstone in the assessment of LV systolic function. Errors in measurement of EF by routine two-dimensional echocardiography (2D ECHO) limit its utility. The VVI is a new technology which uses speckle tracking and other algorithms to track the endocardial border. This may help in more accurate assessment of EF. METHODS Global and regional LVEF was measured in 49 patients using VVI, 2D ECHO and radionuclide-gated single photon emission computed tomography (SPECT). Results were categorised as normal, mild, moderate, or severe LV systolic dysfunction based on American Society of ECHO classification. The results were analysed by appropriate statistical tests for correlations. RESULTS The mean EF was 35 ± 12.08% by VVI, 54.2 ± 19.51% by SPECT (P< 0.001 vs VVI) and 50.3 ± 8.92% by 2D ECHO (P < 0.001 vs VVI). There was weak linear positive correlation between EF measured by VVI and the other modalities (Pearsons correlation coefficient 0.577 for SPECT and 0.573 for 2D; P=0.01). The VVI systematically underestimated the EF compared to SPECT. Greater number of patients had moderate or severe LV systolic dysfunction by VVI (37; 74.5%) than by SPECT (17; 34.7%; P=0.037). We derived a correction factor to calculate SPECT EF from VVI EF as follows: EF (SPECT) = EF (VVI) × 0.9 + 21 or approximately VVI (EF) + 20. CONCLUSION Measurement of EF by VVI is feasible. The VVI underestimated the EF when compared to nuclear-gated SPECT in this study. The accuracy of this technology and the need for a correction factor needs to be assessed in future studies.

Radiation dose from percutaneous transluminal coronary angioplasty procedure performed using flat detector for different clinical angiographic projections

The radiation dose from complex cardiac procedures is of concern due to the lengthy fluoroscopic screening time and vessel complexities. This study intends to assess radiation dose based on angiographic projection and vessel complexities for clinical protocols used in the performance of percutaneous transluminal coronary angioplasty (PTCA). Dose-area product (DAP), reference air kerma (K a,r) and real-time monitoring of tube potentials and tube current for each angiographic projection and dose setting were evaluated for 66 patients who underwent PTCA using a flat detector system. The mean DAP and cumulative K a,r were 32.71 Gy cm2 (0.57 Gy), 51.24 Gy cm2 (0.9 Gy) and 102.03 Gy cm2 (1.77 Gy) for single-, double- and triple-vessel PTCA, respectively. Among commonly used angiographic projections, left anterior oblique 45°-caudal 35° reached 2 Gy in 55 min using a low-dose fluoroscopy setting and 21 min for a medium-dose setting. Use of a low-dose setting for fluoroscopic screening showed a radiation dose reduction of 39% compared with a medium-dose setting.

A dairy worker with fever and an abnormal echocardiogram

Description of the case A 38-year-old male presented with history of progressively increasing dyspnoea of 25 days duration. He gave history of low -grade fever associated with malaise and weight loss over the preceding 6 months. He worked in the dairy industry in the Middle East and returned to India owing to his illness. On clinical examination, he was found to be tachypneic and cachectic. Jugular venous pressure was raised with a prominent ‘a’ wave. There was a short early diastolic murmur over the aortic area. His blood investigations, including renal and liver function tests, were normal. Three sets of blood cultures were sterile. Two-dimensional trans-thoracic and trans-oesophageal echocardiography revealed thickened bicuspid aortic valve cusps, with moderate eccentric aortic regurgitation and an abnormal structure posterior to the left ventricular outflow tract and aorta (figure 1A–C). A small vegetation was seen attached to the fused right–left aortic cusp (supplementary figure 1). The patient was started on appropriate intravenous antibiotics and antifailure medications, and was referred for early surgical treatment. Figure 1 (A) Transthoracic echocardiography parasternal long axis view. (B) Transesophageal echocardiography (mid esophageal level) long axis view

Pseudoaneurysm of the left atrium following infective endocarditis

Transthoracic echocardiogram of a 3-year-old child showed a hypoechoic cavity in the posterior wall of the left atrium communicating with the left ventricle through an orifice in the mitral annulus, suggestive of pseudoaneurysm (Ps), probably the result of infective endocarditis. Three-dimensional echocardiography was helpful to confirm the diagnosis and assess the anatomical relationship of the Ps.

Contralateral approach to iliac artery recanalization with kissing nitinol stents present in the aortic bifurcation.

A 69-year-old man, who had earlier undergone reconstruction of the aortic bifurcation with kissing nitinol stents, presented with occlusion of the left external iliac artery. The occlusion was successfully and safely recanalized using contralateral femoral approach with passage of interventional hardware through the struts of the stents in the aortic bifurcation. Presence of contemporary flexible nitinol stents with open-cell design in the aortic bifurcation is not a contraindication to the use of the contralateral femoral approach.