Epidemiology of Coronary Calcification in the Elderly

最近的研究表明，冠状动脉钙是中年男性和女性冠心病事件的强烈预测因子。我们调查了来自匹兹堡心血管健康研究中心(CHS)的614名(89%)存活队列中冠状动脉钙化的范围和预测因素及其与其他非侵入性动脉粥样硬化指标的关系。这些人的年龄在67-99岁(平均80岁)。已报道的主要发现包括：1)冠状动脉钙化评分与年龄密切相关，但评分范围相当宽泛。10%的人得了零分。2)其他非侵入性血管检查漏掉了许多冠状动脉钙化积分较高的患者。3)除年龄、性别和种族外，传统危险因素对钙化的预测作用相对较弱。我们现在建议跟踪这些个体，以确定冠状动脉钙化是否预测老年心血管疾病和死亡率，以及这是否独立于其他非侵入性疾病测量和传统危险因素。另一种假设是，这种风险在老年时会减弱，因为它可能代表了稳定的斑块，不太容易闭塞或破裂。社区卫生服务将在2001年底结束对结果的确定，因此有必要为这一群体的地方后续行动提供额外资金。除了监测心血管事件，我们还将通过运动试验评估钙化程度的功能意义，并将通过重复EBT扫描来评估4年后的进展，并确定基线评分为0的患者的新钙化率。这些没有钙的人可以被认为是“对冠状动脉疾病免疫”。其具体目的是：1)确定冠状动脉钙化程度是否是老年人总的和发生的心肌梗死以及总的心血管疾病发病率和死亡率的独立预测因子。2)确定312例无临床心血管疾病的老年人冠状动脉钙化的功能意义。3)确定424名幸存者的冠状动脉钙化积分在4年内的进展率，并确定零钙化患者(n=47)是否发生钙化。这项研究可以利用丰富的CHS数据库，以一种省时、经济的方式确定老年人心血管疾病事件与冠状动脉钙化的关系。这是这一老年人群中最大规模的冠状动脉钙化人群研究，可以迅速产生明确的数据，以确定筛查老年人冠状动脉钙化的潜在益处。

Recent studies indicate that coronary artery calcium is a strong predictor of coronary heart disease events in middle- aged men and women. We examined the extent and predictors of coronary artery calcium and its relationship to other non- invasive measures of atherosclerosis in 614 (89 percent) of the surviving cohort from the Pittsburgh center of the Cardiovascular Health Study (CHS). These individuals were ages 67-99 (mean 80). Key findings have been reported and include: 1) Coronary artery calcium scores were strongly age related, yet the range of scores was quite broad. Ten percent had scores of zero. 2) Other non- invasive vascular tests missed many of those with high coronary calcium scores. 3) Other than age, gender and race, traditional risk factors were relatively weak predictors of calcification. We now propose to follow these individuals to determine whether coronary artery calcification predicts cardiovascular disease and mortality in old age, and whether this is independent of other non-invasive measures of disease and traditional risk factors. The alternative hypothesis is that the risk is attenuated in old age, as it may represent stable plaque that is less prone to occlusion or rupture. The CHS is ending the ascertainment of outcomes at the end of 2001, necessitating additional funding for local follow-up of this cohort. In addition to monitoring cardiovascular events, we will evaluate the functional significance of the extent of calcification by an exercise test and will assess progression after 4 years by repeating the EBT scan, and determine the rate of new calcification in those with scores of zero at baseline. Such individuals with no calcium might be regarded as "immune from coronary artery disease." The specific aims are: 1) To determine whether the extent of coronary artery calcium is an independent predictor of total and incident myocardial infarction and total CVD morbidity and mortality in older adults. 2) To determine the functional significance of coronary artery calcification in about 312 of these older adults without clinical cardiovascular disease. 3) To determine the rate of progression over 4 years in coronary artery calcium score in an estimated 424 survivors and to determine if those with zero (n=47) develop any calcification. This study can determine the risk of cardiovascular disease events in relationship to coronary artery calcium in older adults in a time-efficient and cost- effective manner that capitalizes on the rich CHS database. This is the largest population study of coronary artery calcium in this older age group, and can rapidly produce definitive data to determine the potential for benefit of screening older adults for coronary artery calcium.