Can exercise testing in patients with a history of myocardial infarction predict fatal and non-fatal reinfarction?

BACKGROUND AND OBJECTIVES: Exercise testing (ET) is the preferred initial strategy for risk stratification in patients who are able to exercise and have an interpretable electrocardiogram. However, although it is often suggested and widely applied, its usefulness years after myocardial infarction (MI) is questionable. Therefore, this study was designed to assess the value of exercise testing in predicting the risk of fatal or non-fatal reinfarction in patients with chronic stable coronary artery disease (CAD) due to old myocardial infarction. METHODS: Our study involved 766 consecutive stable subjects [mean (SD) age 57 (8.6) years; male: 89%] with stable CAD due to old MI [mean time from MI: 2.8 (0.75) years], who underwent a Bruce treadmill test and whose data were prospectively entered into our institutional database. Patients were followed up for an average of 7 (0.6) years. RESULTS: Reinfarction was observed in 62 patients; 54 non-fatal and 8 (13%) fatal. Relative risk (RR) of cardiac death for subjects with reinfarction was 4.02 [95% confidence interval (CI): 2.46 to 6.55]. Univariate predictors of fatal or non-fatal reinfarction were: multivessel disease (RR 7.99, CI 1.12 to 56.82), EF < 40% (RR 2.91, CI 1.64 to 7.17), ST depression on rest ECG (RR 2.4, CI 1.30 to 4.45), BP increase with exercise < 10 mmHg (RR 2.36, CI 1.41 to 3.93), BP/HR interaction < 10 mmHg + < 85% max (RR 2.16, CI 1.24 to 3.76). Markers of reduced risk of recurrence included low-risk Duke Treadmill Score (RR 0.55, CI 0.33 to 0.91) and EF > or = 40% (RR 0.34, CI 0.19 to 0.60). A Cox regression model with clinical and exercise parameters detected ST depression on rest ECG (RR 1.47, CI 1.07 to 2.02), BP increase with exercise < 10 mmHg (RR 1.41, CI 1.07 to 1.87), low-risk Duke Treadmill Score (RR 0.79, CI 0.60 to 1.02). A model with coronary anatomy and ejection fraction was also able to identify multivessel disease (RR 2.95, CI 1.43 to 6.09), EF < 40% (RR 1.62, CI 1.17 to 2.25) and BP increase with exercise < 10 mmHg (RR 2.53, CI 1.35 to 4.71). CONCLUSIONS: Stable patients with a history of MI represent a very low-risk population in whom reinfarction continues to have a severe prognosis. ET is unable to identify subjects in whom there is a risk of recurrence, especially if only ischemic parameters are evaluated (in this setting, a clinical or anatomic risk stratification may be better). The application of the Duke Treadmill Score could help to identify a very low-risk group in which no additional testing is required. Therefore, routine ET in stable patients with a history of MI is better at identifying a very low-risk group than in predicting recurrence.

Left ventricular dysfunction: a clue to cognitive impairment in older patients with heart failure.

OBJECTIVES: Cognitive impairment has been reported in middle aged patients with end stage heart failure. This cross sectional study assessed the prevalence and determinants of cognitive dysfunction in older patients with mild to moderate heart failure. METHODS: 57 consecutive patients (mean age 76.7 years) with chronic heart failure underwent physical examination, blood chemistry, urinalysis, chest radiography ECG, Doppler echocardiography, and the mini mental state examination (MMSE), mental deterioration battery, depression scale of the Center for Epidemiological Studies (CES-D), Katz activities of daily living, and instrumental activities of daily living 24 hours before hospital discharge. RESULTS: MMSE scores <24 were found in 53% of participants. The MMSE score was associated with left ventricular ejection fraction according to a non-linear correlation, so that cognitive performance was significantly lower in subjects with left ventricular ejection fraction < or =30%. The same pattern of correlation was evidenced between left ventricular ejection fraction and both the attention sub-item of MMSE and the Raven test score. In a multivariate linear regression model, after adjusting for age, sex, and a series of clinical data and objective tests, both age (beta=-0.30; P=0.038) and the natural log of left ventricular ejection fraction (beta=0.58; P=0.001) were associated with the MMSE score. CONCLUSION: Cognitive impairment in older patients with chronic heart failure is common, and independently associated with lower left ventricular ejection fraction. Given the overwhelming incidence and prevalence of heart failure in older populations, early detection of cognitive impairment in these subjects with prompt, intensive treatment of left ventricular systolic dysfunction may prevent or delay a remarkable proportion of dementia in advanced age.

[ST segment depression during recovery after treadmill exercise test in stable patients with previous myocardial infarction]. / ST sottolivellato nella fase di recupero del test da sforzo in pazienti stabili con pregresso infarto miocardico.

BACKGROUND: The significance of exercise-induced ST segment depression is well known while limited data are available on the clinical/prognostic power of ST depression occurring only during recovery. Aim of the study was to clarify the clinical/prognostic value of "recovery only" ST depression in stable patients late from myocardial infarction (AMI) and to determine whether the addition of recovery data to exercise parameters improves the interpretation of exercise test. METHODS: From a population of 766 consecutive patients (mean age: 57.2 +/- 8.6 yrs.; male: 89%) who underwent a Bruce Treadmill test at least 1 year after a Q wave AMI and whose exercise data were prospectively entered in the database of our Institution, 4 different Groups were identified: 1) 99 patients with a negative exercise test; 2) 53 patients with "exercise only" ST depression; 3) 140 patients with "exercise and recovery" ST depression; 4) 31 patients with "recovery only" ST depression. The main clinical and exercise data and a cardiac follow-up (average mean length: 1530 +/- 600 day) were evaluated by one-way analysis of variance, Bonferroni T-test, chi-square, relative risk (RR) with 95% confidence intervals (CI), Kaplan-Meler method and log-rank. RESULTS: Baseline clinical parameters were similar in the 4 Groups except for older age in Group 3 compared to Group 2 (< 0.05) and higher prevalence of anterior AMI in Group 4 compared to others (= 0.004). Patients with exercise and recovery ST depression or with "recovery only" ST depression had significantly less exercise tolerance than patients with negative exercise test or "exercise only" ST depression [exercise duration (< 0.05, Group 1 vs. 3, vs. 4; Group 2 vs. 3), peak rate pressure product (< 0.05), maximal heart rate (< 0.05; Group 1 vs. 2; vs. 3; vs. 4)]. Exercise-induced ST depression was higher and angina was significantly more frequent in patients with exercise and recovery ST depression as well as an high Mark's risk score (< 0.001). Only patients with exercise and recovery ST depression demonstrated significantly higher risk of overall mortality (RR: 1.35, CI: 1.04-1.74), unstable angina (RR: 1.34, CI: 1.09-1.65) or revascularisation procedures (RR: 1.51, CI: 1.25-1.83). Relative risk of patients with "recovery only" ST depression was similar to that of subjects with "exercise only" ST depression. CONCLUSIONS: In stable patients with old Q wave AMI, "recovery only" ST depression is rate, but does represent a true sign of ischemia. It could be associated with indirect indexes of worse ventricular function. The prognostical power of "recovery only" ST depression is mild, although similar to that of "exercise only" ST depression. Moreover the presence of ST depression not only during exercise but also during the recovery phase identifies patients with more severe prognosis. Therefore the inclusion of findings from the recovery phase in the analysis of the exercise test could increase the predictive power of the test itself.

[Identification of viable myocardium by 201Tl scintigraphy: a comparison of methods]. / Identifizierung des vitalen Myokards mit der 201Tl-Szintigraphie: Ein Vergleich der Methoden.

The present study was undertaken to compare four different imaging approaches to evaluate uptake defect reversibility. 24 infarcted patients underwent standard stress/redistribution 201Tl imaging (R1). Then, after reinjection of 37 MBq of 201Tl, patients were re-imaged either after 15 min (R2) 24 h later (R3). A separate rest study (R4) following a new tracer injection was done within 2-3 days. Planar images were obtained in the standard three views and subdivided into 216 segments for qualitative analysis based on a visual score. A semiquantitative analysis based upon circumferential profiles was also applied. A stress defect was found in 127 segments (58.7%). By visual inspection reperfusion was considered to occur in 32.3%, 41.7%, 33.0% and 49.6% of the cases with R1, R2, R3, and R4, respectively. The semiquantitative method showed a high reperfusion only with R1 (62%), while the other procedures proved less effective. No improvement was found with R4. Six patients (25%) showed myocardial viability that was not detected with the early reinjection technique.

Effects of nisoldipine in coronary artery disease: a radioisotopic approach.

The clinical, electrocardiographic, and scintigraphic effects of oral administration of nisoldipine were investigated using two separate study protocols. In the first, the acute effects of nisoldipine were evaluated by means of nuclear ventricolography and demonstrated no deleterious effects on global contractility and an amelioration of several hypokinetic segments. In the second protocol, myocardial perfusion effects were evaluated by means of tomoscintigraphy. An improvement of segmental uptake of thallium was caused by nisoldipine. The addition of atenolol markedly reduced the rate-pressure product and further improved myocardial perfusion.