Early exercise testing after acute myocardial infarction in the elderly: clinical evaluation and prognostic significance

The prognostic value of haemodynamic parameters in the recovery phase of an exercise test. The Finnish Cardiovascular Study

We tested the hypothesis that the change from the peak to recovery values of systolic arterial pressure (SAP recovery) and rate-pressure product (RPP recovery) can be used to predict all-cause and cardiovascular mortality, as well as sudden cardiac death (SCD) in patients referred to a clinical exercise stress test. As a part of the Finnish Cardiovascular Study (FINCAVAS), consecutive patients (n=2029; mean age+/-SD=57+/-13 years; 1290 men and 739 women) with a clinically indicated exercise test using a bicycle ergometer were included in the present study. Capacities of attenuated SAP recovery, RPP recovery and heart rate recovery (HRR) to stratify the risk of death were estimated. During a follow-up (mean+/-s.d.) of 47+/-13 months, 122 patients died; 58 of the deaths were cardiovascular and 33 were SCD. In Cox regression analysis after adjustment for the peak level of the variable under assessment, age, sex, use of beta-blockers, previous myocardial infarction and other common coronary risk factors, the hazard ratio of the continuous variable RPP recovery (in units 1000 mm Hg x b.p.m.) was 0.85 (95% CI: 0.73-0.98) for SCD, 0.87 (0.78-0.97) for cardiovascular mortality, and 0.87 (0.81 to 0.94) for all-cause mortality. SAP recovery was not a predictor of mortality. The relative risks of having HRR below 18 b.p.m., a widely used cutoff point, were as follows: for SCD 1.28 (0.59-2.81, ns), for cardiovascular mortality 2.39 (1.34-4.26) and for all-cause mortality 2.40 (1.61-3.58). In conclusion, as a readily available parameter, RPP recovery is a promising candidate for a prognostic marker.

Adaptation to Low-Intensity Exercise on a Cycle Ergometer by Patients With Acute Myocardial Infarction Undergoing Phase I Cardiac Rehabilitation

BACKGROUND

The adaptation of patients with acute myocardial infarction (AMI) to a phase I rehabilitation program has not been widely assessed.

METHODS AND RESULTS

Forty-two male patients (62+/-8 years) with AMI were classified as exercise tolerant (group A, n=25) or excessive response (systolic blood pressure (SBP) increase >30 mmHg during exercise; group B, n=17). Hemodynamic parameters during exercise using a cycle-ergometer were monitored for the first 3 days. The power of low- and high-frequency components (LF: 0.05-0.2 Hz; HF: 0.2-1 Hz) was analyzed by heart rate variability. Anxiety status was assessed using the Spielberger's State-Trait Anxiety Inventory. Patients in group B were significantly older, had lower cardiac function and a longer hospitalization than group A (p<0.05, respectively). The excessive elevation of SBP on Day 1 decreased and became <30 mmHg on Day 3 in group B. The decreases in HF during exercise on Days 1 and 3 were significantly smaller in group B than in group A (p<0.05 and p<0.05, respectively). The LF/HF ratio on Day 1 was significantly higher in group B than in group A (p<0.05). In group B, the anxiety score before exercise was significantly higher than that at the time of discharge (p<0.05), whereas there was no change in group A.

CONCLUSION

Factors influencing a significant elevation of blood pressure during phase I rehabilitation are age, physical deconditioning, imbalance of autonomic nervous activity and anxiety.

Prognosis and risk indicators of death during a period of 10 years for women admitted to the emergency department with a suspected acute coronary syndrome

AIM

To describe the 10-year prognosis and risk indicators of death in women admitted to the emergency department with acute chest pain or other symptoms raising a suspicion of acute myocardial infarction (AMI). Particular interest was paid to women of <or =75 years of age surviving 1 month after admission, who were judged to have suffered a possible or confirmed acute ischemic event with signs of either minor or no myocardial damage.

PATIENTS

All women admitted to the emergency department at Sahlgrenska University Hospital, Göteborg, during a period of 21 months, due to acute chest pain or other symptoms raising a suspicion of AMI.

METHODS

All the women were followed prospectively for 10 years. The subset described previously underwent a bicycle exercise tolerance test and metabolic screening 3 and 4 weeks, respectively, after admission to the emergency department.

RESULTS

In all, 5362 patients were admitted to the emergency department on 7157 occasions during the time of the survey and 2387 (45%) of them were women. Of these women, 61% were hospitalised and 39% were sent home directly. The overall 10-year mortality for women was 42.5% (55.5% among those hospitalised and 21.8% among those not hospitalised). Of the variables recorded at the emergency department, the following were independently associated with 10-year mortality: age, history of angina pectoris, history of hypertension, history of diabetes, history of congestive heart failure, pathological ECG on admission, degree of initial suspicion of AMI on admission, symptoms of congestive heart failure on admission and other non-specific symptoms on admission. The majority of these risk factors were more markedly associated with prognosis in women discharged directly from the emergency department than in those hospitalised. In the subset aged < or =75 years defined above (n=241), the following were independent predictors of death: a history of AMI and working capacity in a bicycle exercise tolerance test.

CONCLUSION

Among women admitted to hospital due to chest pain or other symptoms raising a suspicion of AMI, 42.5% had died after 10 years. Major risk indicators of death were age, history of cardiovascular disease, pathological ECG on admission and symptoms of congestive heart failure on admission. Women presenting with an acute coronary syndrome but minimal myocardial damage, work capacity and a history of AMI predicted a poor outcome.

Stress testing in the elderly

The ever-increasing number of older patients requiring diagnostic and prognostic assessment for coronary artery disease has necessitated accurate, noninvasive techniques applicable to this age group. Exercise testing, either alone or with radionuclide or echocardiographic imaging, remains a useful tool in elderly patients capable of performing vigorous treadmill or cycle exercise. Fortunately, for the large elderly subset incapable of such exercise, pharmacologic stress testing with dipyridamole, adenosine, or dobutamine offers an excellent alternative. Choosing the most appropriate stress testing modality for a given patient from among the many choices available remains the clinician's challenge.

Ten-year mortality rate in relation to observations at a bicycle exercise test in patients with a suspected or confirmed ischemic event but no or only minor myocardial damage: influence of subsequent revascularization

AIM

Our purpose was to describe symptoms and electrocardiographic findings at a bicycle exercise test 4 weeks after hospitalization for a suspected or confirmed acute ischemic event but either no or only minor myocardial necrosis and its relationship to long-term prognosis and subsequent revascularization.

METHODS

In all patients a symptom-limited bicycle exercise test was performed 4 weeks after discharge from the hospital. The total mortality rate over 10 years was registered.

RESULTS

In all, 770 patients participated in the evaluation. The median age was 63 years, and 34% were women. The most frequent reason for stopping the exercise test was fatigue (69%) followed by dyspnea (33%) and angina pectoris (15%). Angina pectoris was observed in 24% of the patients. ST-segment depression >or=1 mm was observed in 50% and ST-segment depression >or=2 mm was observed in 15% of the patients. The 10-year mortality rate in patients with ST-segment depression >or=2 mm was 24.7%, in patients with ST-segment depression 1.0 to 1.9 mm 33.5%, and in patients with ST-segment depression <1 mm 26.9% (not significant [NS]). Patients with symptoms of angina pectoris had a 10-year mortality rate of 29.4% compared with 27.9% among patients without such symptoms (NS). Patients who had either a drop in systolic blood pressure or failure to raise systolic blood pressure (13%) had a 10-year mortality rate of 36.2% compared with 27.2% among patients without such signs (NS). However, there was a significant association between maximum exercise capacity (in watts) and mortality (P < .0001): 53.8% in the lowest quartile (30-70 W) and 10.2% in the highest (>120 w). When clinical history was considered simultaneously, a low exercise capacity remained as a strong independent predictor of death together with age and a history of either acute myocardial infarction, smoking, or diabetes mellitus. Mechanical revascularization during the subsequent 5 years interacted only with angina pectoris and prognosis; thus patients who had angina during the exercise test had a worse prognosis than those without if they were not being revascularized.

CONCLUSION

Among patients hospitalized with a suspected or confirmed acute ischemic event but either no or only minor myocardial necrosis, we found the maximum working capacity at a symptom-limited bicycle exercise test to be independently associated with the long-term prognosis but not other signs of myocardial ischemia. Further predictors for long-term prognosis were age, a history of acute myocardial infarction, current smoking, and diabetes mellitus. Mechanical revascularization during the subsequent 5 years interacted with the influence of symptoms of angina during test and prognosis.

Which factors determine the long-term outcome among patients with a very small or unconfirmed AMI

AIM

To describe various factors associated with the very long-term prognosis for patients with a very small or an unconfirmed acute myocardial infarction (AMI).

METHODS

Patients below 76 years of age, hospitalized due to suspected AMI who either developed a very small AMI (enzyme elevation<twice upper normal limit and maximum serum (S) aspartate aminotransferase (S-ASAT)<1.4 ukat/l) or an unconfirmed AMI (a suspected ischemic event with no signs of myocardial necrosis) were evaluated at our out-patient clinic. The 10-year mortality was related to the clinical history, age and sex, metabolic factors, diagnosis at hospital discharge, various psychosocial factors, use of medication, current symptoms, underlying reason to the symptoms, maximal working capacity and other observations at bicycle exercise test including signs of myocardial ischemia.

RESULTS

In all, 714 patients (33% women) with a median age of 63 years were included in the analyses. The following appeared as independent risk indicators for 10-year mortality: S-gammaglutamyl transpeptidase (GT) (P<0.0001), age (P<0.0001), current smoking (P<0.0001), a history of previous AMI (P<0.0001), maximal working capacity at bicycle exercise test (P=0.002), and current treatment with digitalis (borderline significance; P=0.022).

CONCLUSION

Among patients with a suspected acute myocardial ischemic event with no or minimal myocardial necrosis, various factors reflecting their age, history of cardiac disease and smoking, liver function, working capacity and possibly use of medication affected their very long-term prognosis.

[Unstable angina in the elderly: clinical, profile, management and mortality at three months. The PEPA Registry Data]

INTRODUCTION AND OBJECTIVES

Few reports in the literature have studied the characteristics and management of unstable angina in the elderly in Spain. The aim of this study was to analyze the clinical characteristics and the use of diagnostic and therapeutic resources in patients > or = 70 years of age.

PATIENTS AND METHODS

A total of 1,551 patients > or = 70 years of age were included out of 4,115 included in the PEPA registry with a follow up of 90 days. These patients were compared with 2,564 < 70 years.

RESULTS

In comparison, the elderly (76 +/- 5 years) versus the younger group (58 +/- 8.5 years) included a higher proportion of women (43 vs 27%), diabetics (30 vs 23%)and hypertensive patients (60 vs 49%) with a lower proportion (p < 0.001) of hypercholesterolemia (33 vs 43%), smoking (40 vs 60%) or family history (9 vs 17%). A previous history of angina (49 vs 35%) or infarction (38 vs31%) and comorbidity was found to be significantly more frequent in the elderly, with a worse previous functional class (NYHA > 2 out of 34 vs 15%). The elderly were treated with fewer invasive procedures (25 vs 44%) or catheterization (26 vs 36%) and they were more frequently controlled with medical treatment (86 vs 83%) although with a lower use of beta blockers (45 vs 53%). The mortality at 3 months was greater in the elderly (7.4 vs 3.0%;p < 0.005) with age being an independent predictor of bad prognosis. Cox multivariate analysis showed the age, ST segment depression, diabetes and heart failure on admission to be predictors of bad prognosis in the elderly.

CONCLUSIONS

A different pattern is observed in cardiovascular risk factors with a more unfavorable clinical profile in elderly patients with unstable angina. The management of these patients is less aggressive and the mortality is greater. Diabetes, heart failure and ST segment depression on admission are independent predictors of bad prognosis in elderly patients.

Exercise myocardial perfusion scintigraphy is useful for evaluating myocardial ischemia even in the elderly

Pharmacologic stress testing is recommended to elderly patients as a valuable alternative to exercise testing. We examined whether exercise testing is as useful for evaluating myocardial ischemia in the elderly as in the young. The consecutive 1,508 patients who underwent exercise 201Tl single-photon emission computed tomography (SPECT) were divided into six age groups: 6-29 years (n = 56), 30-44 (n = 143), 45-54 (n = 311), 55-64 (n = 498), 65-74 (n = 402), and 75-88 (n = 98). Both heart rate and rate-pressure product at peak exercise were significantly lower in patients aged 75-88 than in the other five groups. The frequency of ischemic ST depression was higher in patients aged 75-88 than in those aged 6-74, although the difference was not significant. Moreover, the frequency of 201Tl transient defect was significantly higher in patients aged 75-88 than in those aged 6-74. On the other hand, the sensitivity of ischemic ST depression for 201Tl transient defect was similar among the six groups, but the specificity was significantly lower in patients aged 75-88 than in those aged 6-74. In conclusion, exercise 201Tl SPECT is useful for evaluating myocardial ischemia even in the elderly, but exercise electrocardiography has limitations such as lower specificity in the elderly than 201Tl SPECT.

Risk stratification after acute myocardial infarction in the reperfusion era

Historically, risk stratification for survivors of acute myocardial infarction (AMI) has centered on 3 principles: assessment of left ventricular function, detection of residual myocardial ischemia, and estimation of the risk for sudden cardiac death. Although these factors still have important prognostic implications for these patients, our ability to predict adverse cardiac events has significantly improved over the last several years. Recent studies have identified powerful predictors of adverse cardiac events available from the patient history, physical examination, initial electrocardiogram, and blood testing early in the evaluation of patients with AMI. Numerous studies performed in patients receiving early reperfusion therapy with either thrombolysis or primary angioplasty have emphasized the importance of a patent infarct related artery for long-term survival. The predictive value of a variety of noninvasive and invasive tests to predict myocardial electrical instability have been under active investigation in patients receiving early reperfusion therapy. The current understanding of the clinically important predictors of clinical outcomes in survivors of AMI is reviewed in this article.

Coronary heart disease. Stable and unstable syndromes

CHD in the elderly population will continue to be a source of major concern because of the increasing costs entailed and uncertainties about how the widespread array of diagnostic and therapeutic interventions, often expensive and sometimes hazardous, should be applied. Financial, political, and health policy decisions will continue to occupy much attention, but it is likely that philosophic considerations about aging and death, both from the individual and the societal perspective, will be of paramount importance of deciding how the substantial resources available to the elderly will be used. Randomized, controlled trials are unlikely to play a major role in resolution of management dilemmas in the elderly because of the extraordinary heterogeneity in this population. Registries (databases) involving carefully prospectively collected key variables are likely to be a more effective approach. Critical characterization of complications of procedures, adverse drug reactions, and collection of follow-up data on functional status are among the critical questions, and these can be answered by registry studies. Algorithms and clinical rules developed in younger cohorts are not directly transferable to the elderly cardiovascular patients, further emphasizing the need for prospectively collected, syndrome-specific data. Treatments convincingly demonstrated to reduce mortality in absolute terms more in the elderly than in the young are underused. The heterogeneity of aging emphasizes the wide variability in patients' ability to withstand the stress of procedures and complications of disease and makes clear the need to consider physiologic reserve and biologic age rather than chronology. With better characterization of biologic age and physiologic reserve, more precise estimates of outcomes of therapies and interventions can be made, and patients can be given better information and with their families have more realistic expectations. Better-informed decisions will result. Biologic age will be multifactorial, involving cognitive, emotional, physical, and nutritional attributes as well as specific organ function (lung, kidney, liver) because no single feature can characterize the total elderly patient. The concept of competing risks among the cardiovascular disease being treated, comorbidity, risks of study, and life expectancy will evolve because even the most successful therapy will have limited effect on longevity in the very old. Although important research at the cellular and molecular level will characterize and provide better understanding of the aging process, it is not likely that this basic information will be immediately useful in the management of the large number of elderly patients with major cardiovascular disease. Preventive measures, including physical exercise, mental stimulation, avoidance of depression, good nutrition, and abstinence from tobacco use, are useful approaches to postpone or ameliorate the consequences of aging and allow patients to tolerate cardiovascular diseases better when they become manifest.

[Is the predischarge exercise test valid in patients younger than 40 years old after myocardial infarct for determination of multivascular disease?]

BACKGROUND AND OBJECTIVES

Conventional exercise testing before hospital discharge is the most useful procedure in order to estimate postinfarction prognosis and in detecting multivessel coronary disease which is associated with a poor long-term prognosis. There are no bibliographic reports about it in younger myocardial infarction survivors. The aim of the study was to evaluate sensitivity, specificity and predictive value of symptoms limited maximal exercise testing for multivessel disease diagnosis in young patients after myocardial infarction.

METHODS

Myocardial infarction survivors until the age of 40 performed symptoms limited maximal exercise testing and had a coronary arteriography before hospital discharge.

RESULTS

A total of 100 consecutive patients were included, although in only 83 of them exercise tests and coronariographic studies were done. In this group, multivessel disease was confirmed in 27 patients (15 with positive tests and 12 with normal exercise testing). In the remaining 56 young adults without multivessel involvement, positive tests were only observed in 15 patients and normal tests in 45. Thus, a sensitivity of 56%, specificity of 73%, positive predictive value of 50% and negative predictive value of 77% were found. When patients showed high risk exercise test criteria, the exercise test positive predictive value increased to 80%.

CONCLUSIONS

Due to the lower sensitivity of this test in young myocardial infarction survivors for detecting multivessel artery disease, we remark on the need for predischarge complementary tests such as isotopic, stress echocardiography or coronariography testing.

Limited usefulness of exercise testing and thallium scintigraphy in evaluation of ambulatory patients several months after recovery from an acute coronary event: implications for management of stable coronary heart disease. Multicenter Myocardial Ischemia Research Group

OBJECTIVES

This study evaluated the value of noninvasive testing to predict cardiac events in patients with stable coronary disease after hospital admission (and risk stratification) for an acute coronary event.

BACKGROUND

Exercise testing with thallium perfusion imaging identifies patients with obstructive coronary artery disease and has been used to stratify patients after myocardial infarction. Its usefulness for predicting cardiac events in patients with stable coronary disease after recovery from an acute coronary event was explored.

METHODS

Nine hundred thirty-six patients were enrolled 1 to 6 months after hospital admission for a coronary event. Patients underwent exercise treadmill testing with planar thallium-201 scintigraphy and were followed up for an average of 23 months (range 6 to 43). End points were 1) unstable angina requiring hospital admission, nonfatal myocardial infarction or cardiac death; 2) nonfatal infarction or cardiac death; or 3) cardiac death alone.

RESULTS

Twelve patients died of cardiac causes (1.2%); 32 had a nonfatal myocardial infarction (3.4%); and 79 patients (8.4%) developed unstable angina in the first year. Exercise testing improved proportional hazards models constructed from clinical variables for all three end points (p < 0.05). The perfusion scan further improved models for the end points (nonfatal infarction or cardiac death and cardiac death alone, p < 0.05). However, the exercise test with or without thallium added little to the overall prediction of primary events (area under the receiver operating curve increased from 0.649 to 0.663), and only 2% to 13% of patients with abnormal results either had a nonfatal infarction or died.

CONCLUSIONS

Thallium-201 scintigraphy and exercise testing variables identify patients at risk for subsequent cardiac events. However, the poor predictive performance of these tests in this group of patients with stable coronary disease severely limits their usefulness. These results suggest a limited role for exercise and thallium testing in predicting cardiac events in patients with known coronary disease.