J. P. Smeets

Effect of the haptoglobin phenotype on the size of a myocardial infarct.

We investigated the relation between haptoglobin (Hp) phenotypes and serum levels of various biochemical markers after myocardial infarction in 496 patients. In 122 subjects selected on the basis of short delays until hospitalization, patients with Hp 2-2 had higher cumulated creatine kinase activity than patients with Hp 1-1, or Hp 2-1 (P less than 0.05), as well as higher myoglobin concentrations (P less than 0.02) 12 to 28 hours after admission. Comparison of serum enzyme activities in the remaining 374 patients confirmed that Hp 2-2 patients had significantly higher total creatine kinase, creatine kinase isoenzyme MB fraction, aspartate aminotransferase, and lactate dehydrogenase peak levels. Complications of left ventricular failure were more frequent in these patients (P = 0.05). Our results suggest that Hp 2-2 patients have more severe myocardial infarctions than Hp 1-1 and Hp 2-1 patients, However, no difference in the distribution of haptoglobin phenotype was found between patients who had a myocardial infarction and healthy subjects, indicating that Hp 2-2 does not predispose to the occurrence of infarction.

Prognostic significance of angina pectoris before first acute myocardial infarction

To delineate the clinical significance and prognostic importance of a history of chronic or new onset angina pectoris before acute myocardial infarction (AMI), 732 consecutive patients admitted for a first AMI were studied and divided into 3 groups. Two hundred patients (27%) had chronic angina before AMI (greater than 1 month); 247 patients (34%) had new onset angina before AMI (less than 1 month) and the 285 remaining patients (39%) never had angina before AMI. All clinical characteristics were similar in the group of patients with chronic angina and in the group of patients with new onset angina, including in-hospital mortality (10 vs 9%) and 3-year post-hospital mortality (16 vs 16%). Compared to the 285 patients without angina, the 447 patients with angina before AMI were older, more likely to be women, and had a higher frequency of anterior AMI and early post-infarction angina. Both groups had a similar in-hospital mortality (10 vs 8%, not significant), but patients with angina had a higher 3-year post-hospital mortality (16 vs 7%, p less than 0.001). In the group of patients with angina before AMI who were discharged from the hospital, the comparison of nonsurvivors and survivors showed that the patients who died were older, presented more frequently with a non-Q-wave myocardial infarct and more often had left ventricular failure and complete bundle branch block during hospital stay. Chronic and new onset angina before AMI have the same clinical characteristics and deleterious long-term prognostic significance.

Short-term risk stratification at admission based on simple clinical data in acute myocardial infarction

Abstract Simple clinical data, available in all coronary care units, were recorded in 1,013 consecutive patients with acute myocardial infarction (AMI). In order to identify the patients at highest and lowest risk of mortality during hospital stay, a prognostic index was established from a stepwise logistic discriminant analysis of 10 clinical variables obtained at admission in a consecutive series of 477 patients hospitalized in 1 of 2 coronary care units admitting new patients on alternate days and treating them similarly. This prognostic index was applied to a comparison group of 536 consecutive patients admitted to the other coronary care unit. In the experimental group, 57 of the 477 patients (12%) died (during hospital stay; 60 of the 536 patients (11%) died in the comparison group. As individual variables, age, previous history of AMI, anterior site and left ventricular function on admission were associated witincreased mortality. Three variables were selected from the stepwise logistic discriminant analysis of the experimental group: age; site (anterior = 1, other = 0); and grade of left ventricular function (0 to 4). Prognostic index = 5.9019 − 0.8961 function −0.5708 location −0.0369 age. This index was validated in the comparison group. Patients were allocated into different classes with increasing index values associated with decreasing risk. Three subgroups of patients were identified: high risk of hospital mortality (index ≤1; mortality: 51%), intermediate risk (index 1 to 3; mortality: 18%) and low risk (index >3; mortality: 4%). The use of this simple prognostic index may improve clinical management and selection of patients for intervention trials.

Predictive value of serum enzyme determinations in acute myocardial infarction

Abstract The prognostic significance of serum enzyme measurements in acute myocardial infarction was studied in 146 patients hospitalized shortly after the attack. Creatine kinase (CK), CK-MB, aspartate aminotransferase (ASAT) and lactate dehydrogenase (LDH) were serially determined every four hours during the first three days following admission. Peak enzyme levels correlated well with the cumulated CK release ( r = 0.95, 0.74, 0.70 for CK, ASAT and LDH respectively). Among all enzyme measurements, LDH levels determined when CK reached its peak value provided the best discrimination between acute phase survivors (15 days) and non-survivors. LDH was also the best measurement for identifying patients with ventricular impairment. LDH and ASAT peak levels were more powerful predictors of the patients risk than CK peak levels. CK levels determined later in the course of myocardial infarction were more discriminant, indicating prolonged CK elevation in non-survivors. There was no significant difference in CK-MB levels, nor in cumulated CK-MB amounts for survivors and non-survivors. It is concluded that serum LDH activity is a better predictor of the short term evolution of myocardial infarction than CK levels or infarct size estimations from serial CK determinations.

Prognostic Value of Thallium-201 Stress Myocardial Scintigraphy with Exercise ECG after Myocardial Infarction

The prognostic value of stress electrocardiogram and thallium-201 stress myocardial scintigraphy was analyzed in 224 patients 3 months after a myocardial infarction; both techniques allowed an adequate stratification based on the presence of ST depression or multivessel disease. Combining stress electrocardiogram and stress myocardial scintigraphy data improved the prognostic ability, particularly in patients who associated multivessel disease and ST depression.

Stepwise probit discrimination with specific application to short-term prognosis in acute myocardial infarction.

Abstract Classical discriminant analysis models are appropriate for solving problems of medical diagnosis. When dealing with prognostic situations, we usually assume that individuals suffer from a disease Π, having two (or more) possible outcomes, e.g., Π 1 (remission, survival) and Π 2 (nonremission, death). To solve the problem of outcome prediction on the basis of some available information, we propose a general classification model, applicable to both discrete and continuous data, and including a stepwise variable selection procedure. The model is preferable to classical models, for the difference between the two groups Π 1 and Π 2 is one of risk. The method is applied to the derivation of a short-term prognostic index in acute myocardial infarction.

Critical evaluation of serum uric acid levels in acute myocardial infarction.

Serial measurements of serum uric acid were performed on patients suffering from acute myocardial infarction. Nearly 80 percent of the cases demonstrated a fall in uric acid concentrations during the first two days of hospitalization and a subsequent return to initial levels within six to eight days. There was a relationship between the decrease in uric acid levels and the serum lactate dehydrogenase activity. No evidence could be found that male patients were hyperuricemic as compared to control subjects. However, female patients between 40 and 60 years of age demonstrated significantly higher uric acid levels than healthy women of corresponding ages, even after adjustment for diuretic use.