Increased prevalence of coronary artery disease, silent myocardial ischemia, complex ventricular arrhythmias, atrial fibrillation, left ventricular hypertrophy, mitral annular calcium, and aortic valve calcium in patients with chronic renal insufficiency

Cardiovascular morbidity and mortality is high in patients with chronic renal insufficiency. Patients with chronic renal insufficiency have an increased prevalence of coronary artery disease, silent myocardial ischemia, complex ventricular arrhythmias, atrial fibrillation, left ventricular hypertrophy, mitral annular calcium, and aortic valve calcium than patients with normal renal function. These risk factors for cardiovascular morbidity and mortality contribute to the increased incidence of cardiovascular morbidity and mortality seen in patients with chronic renal insufficiency.     

Prevalence of and association between silent myocardial ischemia and new coronary events in older men and women with and without cardiovascular disease

OBJECTIVES: To investigate the prevalence of silent ischemia (SI) in older men and women detected by 24-hour ambulatory electrocardiograms (AECGs) and the association between SI and new coronary events.DESIGN: In a prospective study, the prevalence of SI detected by 24-hour AECGs and the incidence of new coronary events in 915 older men and 1,874 older women with coronary artery disease (CAD); with hypertension, valvular disease, or cardiomyopathy without CAD; and with no cardiovascular disease were investigated. SETTING: Large long-term healthcare facility. PARTICIPANTS: Nine hundred fifteen men, mean age 80, and 1,874 women, mean age 81. MEASUREMENTS: The prevalence of SI and the incidence of new coronary events in older men and women. RESULTS: SI was present in 34% of men and 33% of women with CAD; 15% of men and 14% of women with hypertension, valvular disease, or cardiomyopathy without CAD; and 6% of men and 5% of women with no cardiovascular disease. At 45-month follow-up in men and 47-month follow-up in women, SI significantly increased the incidence of new coronary events by 2.0 times in men and women with CAD (P <.001); by 1.8 times in men and 1.7 times in women with hypertension, valvular disease, or cardiomyopathy without CAD (P <.001); and by 6.3 times in men (P =.018) and 4.4 times in women (P =.008) with no cardiovascular disease. CONCLUSIONS: SI increases the incidence of new coronary events in older men and women with CAD, with hypertension, valvular disease, or cardiomyopathy without CAD, and with no cardiovascular disease.     

Prevalence and association of ventricular tachycardia and complex ventricular arrhythmias with new coronary events in older men and women with and without cardiovascular disease

BACKGROUND: We report the prevalence of ventricular tachycardia (VT) and of complex ventricular arrhythmias (VA) and their association with new coronary events in older men and women. METHODS: The prevalence of VT and of complex VA detected by 24-hour ambulatory electrocardiograms and the incidence of new coronary events in older persons with coronary artery disease (CAD), with hypertension, valvular disease, or cardiomyopathy without CAD, and with no cardiovascular disease was investigated in 915 men (mean age 80 +/- 8 years) and in 1,874 women (mean age 81 +/- 8 years) in a long-term health care facility. Follow-up was 45 +/- 30 months in men and 47 +/- 30 months in women. RESULTS: The prevalence of VT was 16% in men and 15% in women with CAD, 9% in men and 8% in women with hypertension, valvular disease, or cardiomyopathy without CAD, and 3% in men and 2% in women with no cardiovascular disease. The prevalence of complex VA was 69% in men and 68% in women with CAD, 54% in men and 55% in women with hypertension, valvular disease, or cardiomyopathy without CAD, and 31% in men and 30% in women with no cardiovascular disease. In men and in women with CAD or with hypertension, valvular disease, or cardiomyopathy, VT and complex VA increased the incidence of new coronary events (p <.0001). Within each of the groups of patients, the incidences of new coronary events in men and in women with and without VT or complex VA were similar. CONCLUSIONS: The prevalence of VT and of complex VA were similar in older men and women. VT and complex VA were associated with a higher incidence of new coronary events in men and women with CAD or with hypertension, valvular disease, or cardiomyopathy without CAD, but not in men and women with no cardiovascular disease.     

Incidence of ventricular arrhythmias during transient myocardial ischemia in patients with stable coronary artery disease

To determine the incidence of ventricular arrhythmias related to episodes of transient myocardial ischemia during ambulatory electrocardiographic (ECG) monitoring, 97 patients with stable angina pectoris, angiographically proved coronary artery disease and an abnormal exercise test were studied. A total of 573 episodes with ST segment depression were documented: in 118 episodes (21%) the patients were symptomatic and in 455 (79%) they remained asymptomatic. Ventricular arrhythmias (greater than 5 premature ventricular beats/min, bigeminy, couplets or salvos of premature ventricular beats) occurred during 27 (5%) ischemic episodes in a subset of 10 patients (10%) (group A). The other 87 patients (90%) (group B) showed exclusively ischemic episodes without ventricular arrhythmias. Comparison of patients in group A and group B showed no differences in hemodynamic, angiographic, exercise testing and ambulatory ECG monitoring data. Ischemic episodes with and without ventricular arrhythmias showed a similar duration and amplitude of ST segment depression and a comparable heart rate at the onset of ischemia. Both types of ischemic episodes, with and without arrhythmias, occurred predominantly during the morning hours between 6:00 AM and noon, and both types remained asymptomatic to within similar percentages. The data demonstrate that ventricular arrhythmias are related to transient myocardial ischemia in only a few patients with stable angina pectoris; these arrhythmias are related neither to the degree of ischemia during ambulatory ECG monitoring nor to the occurrence of anginal symptoms.     

Asymptomatic left main coronary artery disease and silent myocardial ischemia

Gathering data on the prognosis, detection, and natural history of asymptomatic left main coronary artery disease with silent myocardial ischemia is difficult. Epidemiologic studies of unexpected death and postmortem studies on silent myocardial infarction suggest this entity to be common. We reviewed 89 consecutive patients with left main coronary artery disease (LMD), defined as 50% or greater reduction of luminal diameter. Of this group, 10 patients (11%) were asymptomatic (ALMD) and 79 patients (88%) were symptomatic (SLMD). All 10 ALMD patients were men, with a mean age of 53 years (range 40 to 65). Treadmill tests (TMT) were performed for: ECG abnormalities six; pre-jogging evaluation two; risk factor evaluation two. The TMT within 9 minutes showed 2 mm or greater ST depression in seven (70%) and 1 to 2 mm in three (30%). Similar TMT results were obtained in the SLMD group, although two patients had negative responses. The degree of stenosis of the left main coronary artery and the frequency of three-vessel disease were similar in both groups. The ejection fraction (EF) and contractile pattern of the left ventricle (LV) were normal in all 10 ALMD patients, but the left ventricular end-diastolic pressure (LVEDP) was abnormal in three (70%). In the SLMD group, 51 (64%) had an abnormal ejection fraction, 50 (65%) had wall motion abnormalities, and 25 (32%) had an abnormal LVEDP.     

冠心病患者无症状心肌缺血阈的分析

目的：探讨冠心病患者无症状心肌缺血阈的临床意义。方法：应用24h动态心电监测，检测62例冠心病患者心肌缺血阈值、MIT的变异度、每次缺血发作持续时间和ST段最大位移，以及昼夜缺血次数。结果：共检出506次心肌缺血，93．5％在ST段压低时心率加快，夜间心肌缺血阈值较低，但缺血时间及ST段压低程度明显重于昼间。结论：心肌缺血有不同的机制，应根据情况给予不同的治疗。     

Clinical significance of exercise-induced silent myocardial ischemia in patients with coronary artery disease

Exercise-induced silent myocardial ischemia is a frequent feature in patients with coronary artery disease. The purpose of this study was to compare the clinical and angiographic characteristics of 269 patients who complained of chest pain during an exercise test (group I) with those of 204 who developed exercise-induced silent myocardial ischemia (group II). Group I patients more frequently had anginal symptoms of class III and IV of the Canadian Cardiovascular Society than did group II patients, who had milder symptoms (p less than 0.001). The only angiographic difference observed between the two groups was a slightly but significantly higher left ventricular end-diastolic pressure in group II patients (p less than 0.05), who also showed a longer exercise duration (p less than 0.01) with a higher heart rate-systolic pressure product (p less than 0.01) and more pronounced ST segment depression at peak exercise (p less than 0.001). Moreover, ventricular ectopic beats during exercise were more frequently observed in group II patients (p less than 0.05). Coronary bypass surgery was performed in 45% of patients of group I and in 24% of patients of group II (p less than 0.05). Survival curves of medically treated patients did not show any statistically significant difference between the two groups. Thus, although patients with a defective anginal warning system may have more pronounced signs of myocardial ischemia and a greater incidence of ventricular arrhythmias during exercise, their long-term prognosis is not different from that of patients who are stopped by angina from the activity that is inducing myocardial ischemia.     

Symptomatic and silent myocardial ischemia during exercise testing in coronary artery disease

During exercise by patients with coronary artery disease (CAD), electrocardiographic evidence of myocardial ischemia may precede the onset of angina or may be unassociated with angina, even at peak levels of stress. However, neither the precise incidence of silent versus symptomatic ischemic episodes nor their interrelation in this setting has been clearly defined. The prevalence of silent and symptomatic myocardial ischemia during treadmill exercise testing was determined in 92 patients with angiographically documented CAD. The study group comprised 77 men (84%) and 15 women (16%) of mean age 57 years (range 32 to 79). Exercise testing resulted in ischemic ST-segment depression (greater than or equal to 1 mm for greater than or equal to 80 ms) only or in association with delayed (greater than or equal to 1 minute) angina in 39 patients (42%); angina only or in association with delayed ST-segment depression occurred in 42 patients (46%); and simultaneous occurrence of angina and ST-segment depression was noted in 11 patients (12%). Analysis of clinical, exercise and angiographic factors (age, sex, history of myocardial infarction, heart rate, maximal ST-segment depression, extent of CAD and left ventricular ejection fraction) revealed no significant correlation with the frequency of symptomatic and silent myocardial ischemia during exercise. Asymptomatic myocardial ischemia occurred commonly during exercise in patients with CAD, but there were no differences in the characteristics of patients with symptomatic and asymptomatic episodes.     

Relation of silent myocardial ischemia to ventricular arrhythmias and sudden death

Silent myocardial ischemia is common in the clinical spectrum of coronary disease. Ambulatory electrocardiographic monitoring has provided the most objective evidence of silent ischemia, but the phenomenon has also been detected in patients with coronary artery disease through analysis of exercise-induced ischemic ST-segment alterations, scintigraphic myocardial perfusion defects and left ventricular wall motion abnormalities. Silent myocardial ischemia frequently occurs in patients with stable angina, unstable angina, myocardial infarction and completely asymptomatic coronary artery disease. In each of these groups, silent ischemia has been associated with an increased risk of subsequent cardiac events. However, it remains unclear whether silent ischemia is directly involved in the occurrence of these events, possibly by provoking ventricular arrhythmias. Only limited data are available on the relation between silent ischemia and arrhythmias in myocardial infarction, vasospastic angina, coronary angioplasty, exercise testing and ambulatory electrocardiography. However, fortuitous ambulatory monitoring coincident with sudden death has detected ischemia associated with lethal arrhythmias in some individual cases. This suggests that an ischemia-arrhythmia association may be important in certain patients at certain times, possibly in combination with other factors.     

Usefulness of echocardiographic left ventricular hypertrophy and silent ischemia in predicting new cardiac events in elderly patients with systemic hypertension or coronary artery disease

The authors performed a prospective study to correlate echocardiographic left ventricular hypertrophy (LVH) and silent ischemia (SI) detected by twenty-four-hour ambulatory electrocardiographic monitoring with new cardiac events in 355 patients, mean age eighty-two +/- eight years, with systemic hypertension or coronary artery disease (CAD). Cardiac events included myocardial infarction, primary ventricular fibrillation, or sudden cardiac death. Mean follow-up was thirty-one +/- seven months (range twelve to forty). Cardiac events occurred in 28 of 147 patients (19%) without LVH or SI (A), in 56 of 113 patients (50%) with LVH and no SI (B), in 16 of 29 patients (55%) with SI and no LVH (C), and in 52 of 66 patients (79%) with LVH and SI (D). Significant p values were p less than 0.001 comparing D with A, D with B, C with A, and B with A; and p less than 0.02 comparing D with C. These data indicate that echocardiographic LVH and SI detected by ambulatory electrocardiographic monitoring are independent risk factors for new cardiac events in elderly patients with systemic hypertension or CAD.     

Effect of beta blockers on incidence of new coronary events in older persons with prior myocardial infarction and diabetes mellitus

Of 613 persons, mean age 79 +/- 9 years, with prior myocardial infarction and diabetes mellitus, 68 (11%) had contraindications to beta blockers; 289 of 545 persons (53%) without contraindications to beta blockers were treated with beta blockers. The Cox regression model showed that significant independent predictors of new coronary events were age (risk ratio 1.02 for an increment of 1 year of age), systemic hypertension (risk ratio 2.0), serum low-density lipoprotein cholesterol > or =125 mg/dl (risk ratio 1.4), serum high-density lipoprotein cholesterol < or =35 mg/dl (risk ratio 1.6), and use of beta blockers (risk ratio 0.73).     

Significance of silent myocardial ischemia during exercise testing in patients with coronary artery disease

To evaluate the significance of ischemic ST-segment depression without associated chest pain during exercise testing, data were analyzed from 2,982 patients from the Coronary Artery Surgery Study (CASS) registry who underwent coronary arteriography and exercise testing and were followed up for 7 years. Patients with proved coronary artery disease (CAD) (at least 70% diameter narrowing) were grouped according to whether they had at least 1 mm of ST-segment depression or anginal chest pain during exercise testing. Four hundred twenty-four had ischemic ST depression without angina (group 1); 232 had angina but no ischemic ST depression (group 2); 456 had both ischemic ST depression and angina (group 3); and 471 had neither ischemic ST depression nor angina (group 4). Sixty-three percent of patients in group 1 and 55% in group 2 had multivessel CAD (difference not significant). The 7-year survival rates were similar for patients in groups 1 (76%), 2 (77%), and 3 (78%), but were significantly better for patients in group 4 (88%, p less than 0.001). Among group 1 patients, survival was related to severity of CAD (p less than 0.001). The 7-year survival rate in group 1 was significantly worse than that in a separate group of 282 patients with ischemic ST depression without angina during exercise testing who had no CAD (95% survival, p less than 0.001). Thus, in patients with silent myocardial ischemia during exercise testing, the extent of CAD and the 7-year survival rate are similar to those of patients with angina during exercise testing. Prognosis is determined primarily by the severity of CAD. In patients without CAD, the survival rate is excellent.     

动态心电图监测老年冠心病无症状心肌缺血的意义

目的:探讨24小时动态心电图(Holter)对老年冠心病患者无症状心肌缺血(SMI)的检出情况。方法:回顾分析我院门诊及住院336例老年冠心病患者的临床情况和Holter资料。结果:(1)常规心电图检出心肌缺血106例(31.55％),Holter检出心肌缺血220例(65.48％);SMI发生率为69.09％,有症状心肌缺血发生率为30.91％;(2)SMI发作有明显生物节律,以清晨6-12时发作频率最高;(3)SMI发作时心率减慢的比例明显低于有症状心肌缺血的(P<0.005);(4)SMI的心律失常检出率为93.4％。结论:Holter可早期发现老年人的无症状心肌缺血,有重要价值。     

Association of platelet function in hypertensive patients with left ventricular hypertrophy, transient myocardial ischemia, and coronary artery disease

The aim of the study was to evaluate how platelet aggregation relates to left ventricular hypertrophy, presence of transient myocardial ischemia and coronary atherosclerosis in essential hypertensive patients. For that purpose platelet aggregation, symptom-limited treadmill-test, echocardiography and coronary angiography were performed in 65 male patients with uncomplicated essential hypertension. Aggregation was monitored both by a turbidometric method and by a method based on real-time estimation of mean aggregate size. Platelet function was also studied in 18 male normotensive subjects. Hypertensive patients with transient myocardial ischemia were characterized by increased platelet sensitivity to adenosine diphosphate, thromboxane A2 mimetic-U46619, serotonin, platelet activating factor and by increased spontaneous aggregability of platelets compared with normotensive subjects and to patients without myocardial ischemia. Platelet aggregation induced by low doses of agonists positively correlated with the degree of left ventricular hypertrophy. This study provides evidence that platelets play an important role in myocardial ischemia. Besides, it was found that platelet activity positively correlated with the degree of left ventricular hypertrophy. This may provide an additional link between left ventricular hypertrophy and coronary heart disease in hypertensive patients.     

Prevalence of echocardiographic left ventricular hypertrophy in persons with systemic hypertension, coronary artery disease, and peripheral arterial disease and in persons with systemic hypertension, coronary artery disease, and no peripheral arterial disease

Echocardiographic left ventricular (LV) hypertrophy was present in 120 of 160 patients (75%) (mean age 72 +/- 8 years) with systemic hypertension, coronary artery disease, and peripheral arterial disease (PAD) and in 43 of 94 age- and gender-matched patients (46%) with systemic hypertension, coronary artery disease, and no PAD (p<0.001). Echocardiographic LV hypertrophy was present in 63 of 68 patients with PAD (93%) with ankle-brachial indexes (ABIs) of <0.60 and in 57 of 92 patients (62%) with ABIs of 0.60 to 0.89 (p<0.001).