GISSI-3 APPI Study Group. Early and six-month outcome in patients with angina pectoris early after acute myocardial infarction (the GISSI-3 APPI [angina precoce post-infarto] study)

Dynamic TIMI risk score for STEMI

Background

Although there are multiple methods of risk stratification for ST‐elevation myocardial infarction (STEMI), this study presents a prospectively validated method for reclassification of patients based on in‐hospital events. A dynamic risk score provides an initial risk stratification and reassessment at discharge.

Methods and Results

The dynamic TIMI risk score for STEMI was derived in ExTRACT‐TIMI 25 and validated in TRITON‐TIMI 38. Baseline variables were from the original TIMI risk score for STEMI. New variables were major clinical events occurring during the index hospitalization. Each variable was tested individually in a univariate Cox proportional hazards regression. Variables with P<0.05 were incorporated into a full multivariable Cox model to assess the risk of death at 1 year. Each variable was assigned an integer value based on the odds ratio, and the final score was the sum of these values. The dynamic score included the development of in‐hospital MI, arrhythmia, major bleed, stroke, congestive heart failure, recurrent ischemia, and renal failure. The C‐statistic produced by the dynamic score in the derivation database was 0.76, with a net reclassification improvement (NRI) of 0.33 (P<0.0001) from the inclusion of dynamic events to the original TIMI risk score. In the validation database, the C‐statistic was 0.81, with a NRI of 0.35 (P=0.01).

Conclusions

This score is a prospectively derived, validated means of estimating 1‐year mortality of STEMI at hospital discharge and can serve as a clinically useful tool. By incorporating events during the index hospitalization, it can better define risk and help to guide treatment decisions.

Gender differences in sympathetic neural activation following uncomplicated acute myocardial infarction

AIMS

To determine whether the magnitude of post-acute myocardial infarction (AMI) sympathetic activation is greater in women (F-AMI) than men (M-AMI).

METHODS AND RESULTS

Both sympatho-humoral activation and female gender are associated with worse outcome in the early phase following AMI. However, women have lower sympathetic output than men. We therefore examined matched groups of F-AMI (18) and M-AMI (18) patients 2-4 days following uncomplicated AMI, then 3 monthly to 9 months; matched normal control (NC) groups comprised M-NC (18) and F-NC (18). Muscle sympathetic nerve activity (MSNA) was measured by microneurography. Muscle sympathetic nerve activity was lower in the F-NC than M-NC (at least P < 0.05) and greater in the two AMI groups than their corresponding NC groups (at least P < 0.001). Muscle sympathetic nerve activity was similar in the F-AMI and M-AMI groups indicating a post-AMI increase in women of about twice that in men (P < 0.0001). Both AMI groups returned to corresponding NC (lower in women) levels by 9 months.

CONCLUSION

Following uncomplicated AMI, women developed a relatively greater magnitude of sympathetic activation lasting until its resolution at 9 months. This is consistent with reports of their worse prognosis observed during this time period, with important potential clinical implications.

The prognostic significance of angina pectoris experienced during the first month following acute myocardial infarction

BACKGROUND

Angina pectoris accompanied by transient ST-segment changes during the in-hospital phase of acute myocardial infarction (AMI) is a well established marker of subsequent cardiac death and reinfarction.

HYPOTHESIS

This study was undertaken to record the prognostic significance of angina pectoris experienced during the first month following discharge from AMI.

METHODS

In all, 803 patients included in the placebo arm of the Danish Verapamil Infarction Trial II were followed up for 18 months in 20 coronary care units in Denmark. The patients were randomized to placebo and were still on study treatment 1 month after discharge. Of these patients, 311 (39%) reported chest pain during the first month following discharge.

RESULTS

Patients with angina pectoris had a significantly increased risk of reinfarction [hazard 1.71; 95%-confidence limit (CL): 1.09, 2.69] and increased mortality risk which, however, only reached borderline statistical significance (hazard 1.52; 95%-CL: 0.96, 2.40). When patients were subdivided according to both angina pectoris and heart failure, those with one or both of these risk markers had significantly increased mortality (p 0.03) and reinfarction (p 0.02) rates compared with patients free of both angina pectoris and heart failure.

CONCLUSION

Patients with postinfarction angina pectoris have a significantly increased morbidity risk.

Long-term prognosis of patients with early post-infarction angina

BACKGROUND

Most studies have shown that early post-infarction angina (EPA) implies an unfavorable long-term prognosis among patients with acute myocardial infarction (AMI). However, some studies have failed to establish a link between the occurrence of EPA and increased mortality and recurrent infarction rates.

METHODS AND RESULTS

In order to evaluate a long-term prognosis in patients with EPA, we assessed the 5-year prognosis of 80 patients with AMI by the presence or absence of EPA. During the 5-year follow up, the occurrence of death, cardiac death, recurrent infarction, unstable angina, heart failure, revascularization and cardiac events were recorded. A cardiac event was defined as an occurrence of any of the following events: cardiac death, recurrent infarction, unstable angina, heart failure and revascularization. Survival analysis showed no differences between patients with and without EPA in the probability of death (p=NS), cardiac death (p=NS), recurrent myocardial infarction (p=NS) and unstable angina (p=NS). Patients with EPA had a higher probability of developing cardiac events (p=0.0285) and undergoing revascularization procedures (p=0.0188).

CONCLUSIONS

EPA increases the risk of patients developing cardiac events and undergoing revascularization procedures, and thereby implies a poor long-term prognosis for patients with AMI.

Nitric oxide homeostasis as a target for drug additives to cardioplegia

The vascular endothelium of the coronary arteries has been identified as the important organ that locally regulates coronary perfusion and cardiac function by paracrine secretion of nitric oxide (NO) and vasoactive peptides. NO is constitutively produced in endothelial cells by endothelial nitric oxide synthase (eNOS). NO derived from this enzyme exerts important biological functions including vasodilatation, scavenging of superoxide and inhibition of platelet aggregation. Routine cardiac surgery or cardiologic interventions lead to a serious temporary or persistent disturbance in NO homeostasis. The clinical consequences are "endothelial dysfunction", leading to "myocardial dysfunction": no- or low-reflow phenomenon and temporary reduction of myocardial pump function. Uncoupling of eNOS (one electron transfer to molecular oxygen, the second substrate of eNOS) during ischemia-reperfusion due to diminished availability of L-arginine and/or tetrahydrobiopterin is even discussed as one major source of superoxide formation. Therefore maintenance of normal NO homeostasis seems to be an important factor protecting from ischemia/reperfusion (I/R) injury. Both, the clinical situations of cardioplegic arrest as well as hypothermic cardioplegic storage are followed by reperfusion. However, the presently used cardioplegic solutions to arrest and/or store the heart, thereby reducing myocardial oxygen consumption and metabolism, are designed to preserve myocytes mainly and not endothelial cells. This review will focus on possible drug additives to cardioplegia, which may help to maintain normal NO homeostasis after I/R.

[Prognostic value of early post-infarction angina in elderly patients]

Although numerous studies have shown that early post-infarction angina was a predictor of poor prognosis in patients with acute myocardial infarction, not a single study has considered this issue in the elderly. The goal of this study, based on a five-year follow-up of elderly patients with acute myocardial infarction, was to determine whether early post-infarction angina in the elderly had any influence on mortality and the incidence of additional coronary events. The study population consisted of 51 patients, aged 60 years or more, with acute myocardial infarction. Early post-infarction angina occurred in 31 subjects (Group 1), while it did not in 20 subjects (Group 2). Patients were monitored for five years and the incidences of death and new coronary events were recorded. A survival analysis was carried out using the Kaplan-Meier method. The survival analysis showed no difference between the observed groups concerning the following probabilities: death (p = 0.9459), cardiac death (p = 0.8253), myocardial reinfarction (p = 0.7405), new coronary events (p = 0.1708), unstable angina (p = 0.1788), myocardial revascularisation (p = 0.0691), and heart failure (p = 0.7047). In contrast to the younger population, where numerous studies have confirmed the link between early post-infarction angina and poor long-term prognosis, such findings could not be replicated in this study of the elderly population.

Quinaprilat during cardioplegic arrest in the rabbit to prevent ischemia-reperfusion injury

OBJECTIVES

This study evaluated intracardiac angiotensin-converting enzyme inhibition as an adjuvant to cardioplegia and examined its effects on hemodynamic, metabolic, and ultrastructural postischemic outcomes.

METHODS

The experiments were performed with an isolated, erythrocyte-perfused, rabbit working-heart model. The hearts excised from 29 adult New Zealand White rabbits (2950 +/- 200 g) were randomly assigned to four groups. Two groups received quinaprilat (1 microg/mL), initiated either with cardioplegia (n = 7) or during reperfusion (n = 7). The third group received l-arginine (2 mmol/L) initiated with cardioplegia (n = 7). Eight hearts served as a control group. Forty minutes of preischemic perfusion were followed by 60 minutes of hypothermic arrest and 40 minutes of reperfusion.

RESULTS

All treatments substantially improved postischemic recovery of external heart work (62% +/- 6%, 69% +/- 3%, and 64% +/- 5% in quinaprilat during cardioplegia, quinaprilat during reperfusion, and l-arginine groups, respectively, vs 35% +/- 5% in control group, P <.001) with similarly increased external stroke work and cardiac output. When administered during ischemia, quinaprilat significantly improved recovery of coronary flow (70% +/- 8%, P =.028 vs quinaprilat during reperfusion [49% +/- 5%] and P =.023 vs control [48% +/- 6%]). l-Arginine (55% +/- 7%) showed no significant effect. Postischemic myocardial oxygen consumption remained low in treatment groups (4.6 +/- 1.2 mL. min(-1). 100 g(-1), 6.0 +/- 2.2 mL. min(-1). 100 g(-1), and 4.7 +/- 1.6 mL. min(-1). 100 g(-1) in quinaprilat during cardioplegia, quinaprilat during reperfusion, and l-arginine groups, respectively, vs 4.2 +/- 0.8 mL. min(-1). 100 g(-1) in control group), even though cardiac work was markedly increased. High-energy phosphates, which were consistently elevated in all treatment groups, showed a significant increase in adenosine triphosphate with quinaprilat during ischemia (2.24 +/- 0.14 micromol/g vs 1.81 +/- 0.12 micromol/g in control group, P =.040). Ultrastructural grading of mitochondrial damage revealed best preservation with quinaprilat during ischemia (100% [no damage], P =.001 vs control).

CONCLUSION

These experimental findings have clinical relevance regarding prevention of postoperative myocardial stunning and low coronary reflow in patients undergoing heart surgery.

Bivalirudin administration during percutaneous coronary intervention: emphasis on high-risk patients

In a large phase III study of patients with unstable angina treated with percutaneous transluminal coronary angioplasty (PTCA), the thrombin-specific anticoagulant bivalirudin produced relative risk reductions of 22% (p = 0.039) for ischemic complications and 62% (p < 0.001) for bleeding complications compared with heparin. Subsequent reports have shown that between-treatment differences favoring fewer complications with bivalirudin also extend to high-risk patients. Early heparinization promotes heparin resistance and decreases activated clotting time achieved during PTCA. These effects are relevant to patients with postinfarction angina, which is associated with a greater likelihood of early vessel closure and procedural failure. In 1006 patients with one or both of these risk factors, bivalirudin significantly reduced combined ischemic and bleeding complications compared with heparin (8.6% vs 18%, p < 0.001). Treatment separations favoring bivalirudin increased with risk, suggesting decreased heparin effectiveness in patients at heightened risk. Findings in three additional risk groups-women, the elderly, and patients not receiving glycoprotein IIb/IIIa inhibitors-also showed fewer complications with bivalirudin therapy. Preliminary data suggest that bivalirudin can be combined safely with glycoprotein IIb/Illa antagonists in percutaneous coronary intervention (PCI), including PTCA. An ongoing trial is aimed at determining the efficacy and safety of heparin with planned glycoprotein IIb/IIIa therapy versus bivalirudin with provisional glycoprotein IIb/IIIa therapy. The use of bivalirudin in patients with heparin-induced thrombocytopenia also is being evaluated after favorable findings in early compassionate-use studies. The fact that between-treatment differences favoring bivalirudin were especially outstanding among the high-risk patients considered in this review reinforces the impression that bivalirudin is a promising and unprecedented alternative to heparin in PCI.

Long-term prognostic importance of hyperkinesia following acute myocardial infarction. TRACE Study Group. TRAndolapril Cardiac Evaluation

The long-term prognostic importance of hyperkinesia is unknown following an acute myocardial infarction (AMI). The American Society of Echocardiography recommends that hyperkinesia should not be included in calculation of wall motion index (WMI). The objective of the present study was to determine if hyperkinesia should be included in WMI when it is estimated for prognostic purposes following an AMI. Six thousand, six hundred seventy-six consecutive patients were screened 1 to 6 days after AMI in 27 Danish hospitals. WMI was measured in 6,232 patients applying the 9-segment model and the following scoring system: 3 for hyperkinesia, 2 for normokinesia, 1 for hypokinesia, 0 for akinesia, and -1 for dyskinesia. All patients were followed with respect to mortality for at least 3 years. WMI was calculated in 2 different ways: 1 including hyperkinetic segments (hyperkinetic-WMI) and the other excluding nonhyperkinetic segments (nonhyperkinetic-WMI) by converting the hyperkinetic segments to normokinetic segments. Hyperkinesia occurred in 736 patients (11.8%). WMI was an important prognostic factor (relative risk 2.49; p = 0.0001) for long-term mortality together with heart failure, history of hypertension, angina, or diabetes, previous AMI, age, thrombolytic therapy, arrhythmias, and bundle branch block. In a multivariate analysis including nonhyperkinetic-WMI, hyperkinesia was associated with a relative risk of 0.84, which was statistically significant (confidence intervals 0.74 to 0.96; p = 0.01). When hyperkinesia was included, both in WMI (hyperkinetic-WMI) and as an independent variable, no additional prognostic information (relative risk 0.93; p = 0.26) was obtained. An echocardiographic evaluation shortly after an AMI gave important prognostic information, especially if the information concerning hyperkinesia was included. If WMI is used for prognostic purposes, hyperkinesia should be included in calculation of the index.