Coronary Intravascular Lithotripsy Versus Rotational Atherectomy in an Asian Population: Clinical Outcomes in Real-World Patients

Background and Objectives@#We compared real-world clinical outcomes of patients receiving intravascular lithotripsy (IVL) versus rotational atherectomy (RA) for heavily calcified coronary lesions. @*Methods@#Fifty-three patients who received IVL from January 2017 to July 2020 were retrospectively compared to 271 patients who received RA from January 2017 to December 2018.Primary endpoints were in-hospital and 30-day major adverse cardiovascular events (MACE). @*Results@#IVL patients had a higher prevalence of acute coronary syndrome (56.6% vs 24.4, p<0.001), multivessel disease (96.2% vs 73.3%, p<0.001) and emergency procedures (17.0% vs 2.2%, p<0.001) compared to RA. In-hospital MACE (11.3% vs 5.9%, p=0.152), MI (7.5% vs 3.3%, p=0.152), and mortality (5.7% vs 3.0%, p=0.319) were not statistically significant. 30-day MACE was higher in the IVL cohort vs RA (17.0% vs 7.4%, p=0.035). Propensity score adjusted regression using IVL was also performed on in-hospital MACE (odds ratio [OR], 1.677; 95% confidence interval [CI], 0.588–4.779) and 30-day MACE (OR, 1.910; 95% CI, 0.774–4.718). @*Conclusions@#These findings represent our initial IVL experience in a high-risk, real-world cohort. Although the event rate in the IVL arm was numerically higher compared to RA, the small numbers and retrospective nature of this study preclude definitive conclusions. Theseclinical outcomes are likely to improve with greater experience and better case selection, allowing IVL to effectively treat complex calcified coronary lesions.

Cholesterol goal achievement and lipid-lowering therapy in patients with stable or acute coronary heart disease in Singapore: results from the Dyslipidemia International Study II

INTRODUCTION@#Dyslipidaemia is a major risk factor for coronary heart disease (CHD). There is a lack of data on the extent of lipid abnormalities and lipid-lowering therapy (LLT) in Singapore.@*METHODS@#The Dyslipidemia International Study (DYSIS) II was a multinational observational study of patients with stable CHD and hospitalised patients with an acute coronary syndrome (ACS). A full lipid profile and use of LLT were documented at baseline, and for the ACS cohort, at four months post-hospitalisation.@*RESULTS@#325 patients were recruited from four sites in Singapore; 199 had stable CHD and 126 were hospitalised with an ACS. At baseline, 96.5% of the CHD cohort and 66.4% of the ACS cohort were being treated with LLT. In both cohorts, low-density lipoprotein cholesterol (LDL-C) levels were lower for the treated than the non-treated patients; accordingly, a higher proportion of patients met the LDL-C goal of < 70 mg/dL (CHD: 28.1% vs. 0%, p = 0.10; ACS: 20.2% vs. 0%, p < 0.01). By the four-month follow-up, a higher proportion of the ACS patients that were originally not treated with LLT had met the LDL-C goal (from 0% to 54.5%), correlating with the increased use of medication. However, there was negligible improvement in the patients who were treated prior to the ACS.@*CONCLUSION@#Dyslipidaemia is a significant concern in Singapore, with few patients with stable or acute CHD meeting the recommended European Society of Cardiology/European Atherosclerosis Society goal. LLT was widely used but not optimised, indicating considerable scope for improved management of these very-high-risk patients.

Risk factors for cardiovascular events among Asian patients without pre-existing cardiovascular disease on the renal transplant wait list.

INTRODUCTION: For suitable end-stage renal failure (ESRF) patients, renal transplantation gives better long term survival and quality of life as compared to dialysis. Prior to entry into the renal transplant wait list, potential candidates are screened for the presence of cardiovascular disease. However, the waiting time on the transplant list is long, and interval screening for cardiac fitness for surgery is not well defined. We aim to study the risk factors for the development of a cardiovascular event (CVE) and the time interval from recruitment to onset of a CVE that resulted in their removal from the transplant wait list. METHODS: A retrospective study of all patients registered under the cadaveric renal transplant waiting list in Singapore General Hospital (SGH) from 16th April 1987 to 31st October 2010. We identified patients who developed a CVE among this cohort. We compared the demographics and clinical characteristics of patients who experienced a CVE versus those who did not. Univariable and multivariable cox regression were performed to investigate the significant variables for the development of a CVE. The time to development of CVE was estimated using Kaplan Meier estimation and log-rank test was used to compare the time to CVE between those with diabetes mellitus and those without. RESULTS: 1265 patients were enrolled in this study. 273 patients dropped out of the wait list due to medical reasons or death, of which 38.8% were due to CVE. The mean and median time duration from recruitment into the waiting list to development of a CVE was 14.42 (95% CI 13.72 to 15.11) and 15.69 (95% CI 13.86 to 17.51) years respectively. For patients with diabetes mellitus, this was 8.22 (95% CI 6.30 to 10.14) and 8.16 (95% CI 4.95 to 11.36) years respectively. Factors associated with an increased risk of developing a CVE included male gender (adjusted HR 2.21, 95% CI 1.43 to 3.41, p<0.001), presence of diabetes mellitus (adjusted HR 5.13, 95% CI 2.85 to 9.24, p<0.001) and patients who were either not working or working part-time as compared to their full-time counterparts (adjusted HR 1.76, 95% CI 1.14 to 2.72, p=0.010). In addition, hazard ratio for CVE significantly increased with advancing age quartile (p<0.001 by log rank test for trend). CONCLUSION: A significant proportion of patients exited from the renal transplant wait list due to a CVE. Being male, age 37 years old or more, presence of diabetes mellitus and non-working or part-time workers as compared to full-time workers were found to increase the risk of developing a CVE during the wait period for transplantation. The presence of diabetes mellitus significantly shortened the time to development of a CVE.

Lifetime cost-effectiveness analysis of ticagrelor in patients with acute coronary syndromes based on the PLATO trial: a Singapore healthcare perspective

<p><b>INTRODUCTION</b>Ticagrelor is a novel antiplatelet drug developed to reduce atherothrombosis. The PLATO trial compared ticagrelor and aspirin to clopidogrel and aspirin in patients with acute coronary syndromes (ACS). Ticagrelor was found to be superior in the primary composite endpoint of cardiovascular death, myocardial infarction or stroke, without increasing major bleeding events. The current study estimates the lifetime cost-effectiveness of ticagrelor relative to generic clopidogrel from a Singapore public healthcare perspective.</p><p><b>METHODS</b>This study used a two-part cost-effectiveness model. The first part was a 12-month decision tree (using PLATO trial data) to estimate the rates of major cardiovascular events, healthcare costs and health-related quality of life. The second part was a Markov model estimating lifetime quality-adjusted survival and costs conditional on events during the initial 12 months. Daily drug costs applied were SGD 1.05 (generic clopidogrel) and SGD 6.00 (ticagrelor). Cost per quality-adjusted life years (QALY) was estimated from a Singapore public healthcare perspective using life tables and short-term costs from Singapore, and long-term costs from South Korea. Deterministic and probabilistic sensitivity analyses were performed.</p><p><b>RESULTS</b>Ticagrelor was associated with a lifetime QALY gain of 0.13, primarily driven by lower mortality. The resulting incremental cost per QALY gained was SGD 10,136.00. Probabilistic sensitivity analysis indicated that ticagrelor had a > 99% probability of being cost-effective, given the lower recommended WHO willingness-to-pay threshold of one GDP/capita per QALY.</p><p><b>CONCLUSION</b>Based on PLATO trial data, one-year treatment with ticagrelor versus generic clopidogrel in patients with ACS, relative to WHO reference standards, is cost-effective from a Singapore public healthcare perspective.</p>

Risk assessment models in acute coronary syndromes and their applicability in Singapore

Risk prediction models are critical in managing patients with acute coronary syndromes (ACS) as they identify high-risk patients who benefit the most from targeted care. We discuss the process of developing and validating a risk prediction model as well as highlight the more commonly used models in clinical practice currently. Finally we conclude by outlining the importance of creating a risk prediction model based on a Singapore population of ACS patients so as to further improve patient, hospital and research outcomes.