published_or_final_version / abstract / toc / Community Medicine / Doctoral / Doctor of Philosophy

published_or_final_version / Community Medicine / Doctoral / Doctor of Philosophy

Acute coronary syndrome (ACS), a term used to cover a group of clinical symptoms compatible with acute myocardial ischemia, represents a high-risk group of patients with coronary heart disease (CHD). To improve quality of care, international guidelines for the management of ACS have been established and are updated regularly. In the era of evidence based medicine, adherence to therapeutic guidelines is essential for optimal care of ACS patients. However, most data on ACS epidemiology, treatment and outcomes are derived from western population. There are limited data in Chinese population in terms of prevalence, presentation, response to treatment and clinical outcome. / Among 624 patients finished Short Form (SF)-36 questionnaires, health related quality of life (HRQoL) were compared between patients underwent PCI versus those treated conservatively across 3 age groups (<60, 60-79 and ≥80 years). PCI was performed in 73.6%,55.7% and 21.3% in patients aged <60,60-79 and older than 80 years, respectively (p<0.01). Elderly patients were more likely to be female (16.9 vs. 35.4 vs. 54.6%, p<0.01) and had more co-morbidities (p<0.01). Older patients were less likely to undergo angiography (84.8 vs. 65.2 vs. 24.8%, p<0.01). Baseline HRQoL decreased with advancing age (p<0.01). However, elderly patients who underwent PCI-experienced the most improvement in physical health than younger age groups. PCI was an independent predictor (OR, 1.79,95% CI: 1.10-2.92) of better physical health status at 6 months. In conclusion, elderly ACS patients who underwent PCI experienced the most improvement in physical health compared to younger patients. Our findings suggest that age per se should not deter against revascularization because of potential benefits in HRQOL. / In summary, this is the first registry which described patients' characteristics, treatment and management practices, and hospital outcomes over the whole spectrum of ACS in Hong Kong. The study identified gaps between guideline and clinical practice as well as the reasons of these gaps, and measured the impact of such gaps on the outcomes of patients with ACS. Compared with internationally reported data, Hong Kong patients are different in terms of age and risk factors distribution. Treatment gaps exist between international therapeutic guideline recommendations and clinical practice, especially among the high risk population, the elderly and female patients. Better understanding and narrowing these gaps between guideline and practice will lead to improvement in quality of care and clinical outcomes. Increase use ofrisk stratification models and health status assessments may improve decision making in the management of ACS. / Patients with ACS were divided into low- and high-predicted risk of mortality at 6 months using the GRACE risk score (≥142.5 was defined as high-risk). We evaluated the use of in-hospital angiography, revascularization, anti-platelet, angiotensin converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB), beta-blockers and statins therapy between high and low-risk patients. There were 259 patients in the high- and 742 in the low-risk groups. Paradoxically, high-risk compared to low-risk patients were less likely to underwent coronary angiography and/or revascularization during the index hospitalization (33% vs. 64% and 25% vs. 50%, both p<0.01). Hospital initiated pharmacotherapies are also lower in high-risk patients (24% vs. 55% for c1opidogrel, 49% vs. 58% for ACEI/ARBs, 54% vs. 69% for beta-blockers and 56% vs. 77% for statins; all p<0.01). After adjustment, high-risk patients remained less likely to undergo revascularization (adjusted odds ratio [OR], 0.47; 95% CI, 0.33-0.73, p<0.001) than low-risk patients. Advanced age, increased creatinine level and higher GRACE score were independent predictors for failure to administer evidence-based therapies. Thus, patients with ACS at high risk of mortality were paradoxically less likely to undergo revascularization or receive medications according to guidelines. Better adherence to evidence-based therapies in high-risk patients may improve clinical outcome and quality of health care. / The Hong Kong ACS registry was designed to investigate epidemiology, treatment and outcome of ACS patients under current medical care system, it was conducted in a university affiliated teaching hospital from February 2006 to December 2009. Clinical characteristics and treatment data were collected at baseline, 30 days and 6 months after onset in a standard defined case report form. SF-36 questionnaire was completed after admission and at 6 months. Outcomes were evaluated mortality and morbidity in clinical aspect and quality of life in aspect of health status. / The Main findings were as followed: Totally 1001 patients admitted with ACS were recruited. Among all patients enrolled, 31.7% were diagnosed with ST-segment elevation myocardial infarction, 42.7% with non-S'T-segrnent myocardial infarction and 21.6% with unstable angina. The median age was 72 (interquartile range 61-79) years; 77.2% were >60 years old, and 31.5% were women. / Women presented more often with NSTE-ACS than men (77.3% of women vs. 63.2% of men, p<0.001). Despite having greater cornorbidities including hypertension, diabetes, hypercholesterolemia, renal impairment and history of heart failure etc., women were observed to have higher GRACE (global registry of acute coronaryevents) score than men (128+/-32 vs. 118+/-37, p score than men (128+/-32 vs. 118+/-37, p<0.01). Women were less likely to be assigned invasive procedures (43.3% vs. 62.9%, p<0.001) as well as pharmacotherapies such as clopidogrel (41.1% vs. 58.8%, p<0.001), glycoprotein (GP) IIb/IIIa antagonists (5.3% vs. 11.6%, p=0.001) and statins (64.1% vs. 77.2%, p<0.01) et al. than men. For in-hospital mortality, the adjusted odds ratio for men compared to women was similar (odds ratio [OR]: 1.32, 95% CI: 0.62-2.83, p=0.47). The higher 6 month mortality and major cardiac events rate in women were not significant after adjusting for differences in clinical characteristics and percutaneous coronary intervention (PCI) (OR=1.02; 95% CI 0.62 to 1.68; p=0.95). In summary, there were differences in baseline characteristics and in the management of women and men admitted for ACS. Advanced age and high comorbidities prevalence could explain most of the difference between genders suggesting that decision making bias in clinical practice is anti-age but not anti-female. Overall, in-hospital and 6 months mortality was similar for women and men after adjustments. / Li, Rujie. / "December 2010." / Adviser: Cheuk-Man Yu. / Source: Dissertation Abstracts International, Volume: 73-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 145-166). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.