Estimated gain in life expectancy. A simple tool to select optimal reperfusion treatment in individual patients with evolving myocardial infarction

Association of red cell distribution width with noninfarct-related artery-chronic total occlusion in acute myocardial infarction patients

Objective: The presence of chronic total occlusion (CTO) in noninfarct-related artery (non-IRA) is an independent predictor of mortality in acute myocardial infarction (AMI). We investigated whether red cell distribution width (RDW) levels are associated with presence of non-IRA-CTO in AMI (ST-elevation myocardial infarction [STEMI] and non-STEMI). Patients and methods: Patients (n = 858) were categorized into three groups: single vessel disease, multivessel disease (MVD) without CTO and MVD with CTO. Results: MVD with CTO group had higher RDW levels than single vessel disease and MVD without CTO groups (14.87 ± 1.09% vs 13.82 ± 1.01% and 13.87 ± 0.87%, respectively, p < 0.001). In-hospital mortality was also higher in patients with MVD with CTO (p < 0.001). On multivariate analysis, RDW (odds ratio [OR]: 1.761; p < 0.001), age (OR: 1.04; p < 0.001), creatinine (OR: 3.524; p = 0.027), current smoker (OR: 0.489; p = 0.022), hemoglobin (OR: 0.826; p = 0.044), and non-STEMI (OR: 3.065; p < 0.001) were predictors of occurrence of non-IRA-CTO. Conclusion: Increased RDW is independently associated with presence of non-IRA-CTO in AMI patients.

Cost-effectiveness of computed tomography coronary angiography versus conventional invasive coronary angiography

OBJECTIVES

To determine the costs and cost-effectiveness of a diagnostic strategy including computed tomography coronary angiography (CTCA) in comparison with invasive conventional coronary angiography (CA) for the detection of significant coronary artery disease from the point of view of the healthcare provider.

METHODS

The average cost per CTCA was determined via a micro-costing method in four French hospitals, and the cost of CA was taken from the 2011 French National Cost Study that collects data at the patient level from a sample of 51 public or not-for-profit hospitals.

RESULTS

The average cost of CTCA was estimated to be 180<euro> (95 % CI 162-206<euro>) based on the use of a 64-slice CT scanner active for 10 h per day. The average cost of CA was estimated to be 1,378<euro> (95 % CI 1,126-1,670<euro>). The incremental cost-effectiveness ratio of CA for all patients over a strategy including CTCA triage in the intermediate risk group, no imaging test in the low risk group, and CA in the high risk group, was estimated to be 6,380<euro> (95 % CI 4,714-8,965<euro>) for each additional correctly classified patient. This strategy correctly classifies 95.3 % (95 % CI 94.4-96.2) of all patients in the population studied.

CONCLUSIONS

A strategy of CTCA triage in the intermediate-risk group, no imaging test in the low-risk group, and CA in the high-risk group, has good diagnostic accuracy and could significantly cut costs. Medium-term and long-term outcomes need to be evaluated in patients with coronary stenosis potentially misclassified by CTCA due to false negative examinations.

Thrombolytic therapy guided by a decision analysis model: are there potential benefits for patient management?

BACKGROUND

Although thrombolytic therapy improves the outcome of myocardial infarction, it is associated with increased risks of stroke and bleeding; these risks may outweigh the benefits of therapy. The risks and benefits of thrombolysis, for any individual clinical situation, can be explicitly estimated by means of decision analysis.

HYPOTHESIS

The aim of this study was to compare the actual use of thrombolytic agents for suspected acute myocardial infarction (AMI) with the management preferred by a decision analysis model.

METHODS

Admission data prospectively obtained in 262 consecutive patients admitted to a rural community hospital's coronary care unit with suspected AMI, as well as clinical decisions and outcomes, were reviewed and analyzed.

RESULTS

Seventeen deaths from AMI and no major strokes were observed, compared with 18.30 deaths and 0.85 major strokes predicted by a decision analysis model. Forty-seven of 84 patients with confirmed AMI and 3 of 178 without AMI were given a thrombolytic agent, compared with 65 patients with and 7 without AMI who had decision analysis-guided therapy. Decision analysis-guided therapy could have saved 3.7 additional lives and gained 29.6 life years, but produced 0.4 extra strokes. Changing the quality adjustment for stroke or heart failure would not have altered the treatment preferred by decision analysis in any of the 262 cases studied. Some patients were predicted to benefit considerably from thrombolysis with little extra risk of stroke and vice versa: all cases must, therefore, be assessed individually.

CONCLUSIONS

A decision analysis model can guide thrombolytic therapy by promptly defining its risks and benefits.

Electrocardiogram dynamics for risk stratification in ST-segment elevation myocardial infarction—immediate and serially updated information on outcome

Early and serially updated predictions of final infarct-size and clinical outcome--before, during and after reperfusion treatment of ST-elevation myocardial infarction might allow a more individualized treatment: High-risk patients with a predicted major loss of viable myocardium can be identified immediately or during therapy, at a stage when treatment may still be modified; and low-risk patients with predictions of small infarcts and good outcome already after standard primary reperfusion therapy can be identified and thereby avoid a possibly harmful intensified treatment. The necessary information for such predictions seem to be available from the standard 12-lead ECG and from ST-segment monitoring. Today this information, however, is not readily available in clinical practice. Automated algorithms need to be engineered for a broader use and for possibilities of a refined triage and thus for a more individualized strategy of reperfusion therapy.

Sustained Benefit 20 Years After Reperfusion Therapy in Acute Myocardial Infarction

OBJECTIVES

The goal of this research was to clarify whether the benefit of reperfusion therapy for myocardial infarction was sustained long-term and to assess the gain in life expectancy by reperfusion therapy.

BACKGROUND

Reperfusion therapy in acute myocardial infarction reduces infarct size and increases hospital survival.

METHODS

We analyzed the 20-year outcome of 533 patients (mean age 56 years; 82% men) who were randomized to either reperfusion therapy or conventional therapy during the years 1981 to 1985.

RESULTS

Mean follow-up was 21 years (range 19 to 23 years). At follow-up, 101 patients (36%) of the 269 patients allocated to reperfusion treatment and only 71 patients (26%) of the 264 conventionally treated patients were alive (p = 0.02). The cumulative 10-, 15-, and 20-year survival rates were 69%, 48%, and 37% after reperfusion therapy and 59%, 38%, and 27% in the control group, respectively (p = 0.005). Life expectancy of the reperfusion group was 15.2 years versus 12.4 years in the conventionally treated group (p < 0.0001). Myocardial re-infarction and subsequent coronary interventions were more frequent after reperfusion therapy, particularly during the first year. In multivariable analysis, reperfusion therapy was an important independent predictor of lower mortality at long-term follow-up (hazard ratio 0.7; 95% confidence interval 0.6 to 0.8). Other independent predictors of mortality were age, impaired left ventricular function, multivessel disease, infarct size, and inability to perform an exercise test at the time of discharge.

CONCLUSIONS

This is the first study demonstrating sustained (20-year) improved survival after reperfusion therapy. The gain in life expectancy was almost three years, representing about one-third of the life-years lost by myocardial infarction.

Combining baseline clinical descriptors and real-time response to therapy: the incremental prognostic value of continuous ST-segment monitoring in acute myocardial infarction

BACKGROUND

Clinical descriptors and ST-segment recovery variables hold prognostic information for clinical outcome after thrombolysis for acute myocardial infarction (MI). We sought to define the incremental prognostic value of continuous 12-lead ST-segment monitoring variables to clinical risk descriptors identified by the Global Utilization of Streptokinase and TPA (alteplase) for Occluded Coronary Arteries (GUSTO-I) trial 30-day mortality analysis.

METHODS

Of 1,777 patients enrolled in continuous ST-segment substudies from the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI-9), GUSTO-I, Duke University Clinical Cardiology Study (DUCCS-II), Integrilin to manage Platelet Aggregation to Combat Thrombus in Acute Myocardial Infarction (IMPACT-AMI), Promotion of Reperfusion by Inhibition of Thrombin During Myocardial Infarction Evolution (PRIME), and Platelet Aggregation Receptor Antagonist Dose Investigation and Reperfusion Gain in Myocardial Infarction (PARADIGM) trials, 825 patients qualified for assessment of time to recovery. ST recovery variables analyzed were time to stable ST-recovery and late ST elevation. Patients who were at low clinical risk (n = 261) had no high-risk descriptors, and patients at high clinical risk (n = 564) had at least 1 of these high-risk descriptors: age >or=70 years, systolic blood pressure <or=110 mm Hg, heart rate >or=90 beats/min, anterior MI, or previous MI. High (n = 90), moderate (n = 318), and low (n =417) ST-risk groups were defined by the presence of both slow ST recovery and late ST elevation, one or the other, or neither, respectively. End points analyzed were inhospital death and combined death, reinfarction, or congestive heart failure.

RESULTS

There was a trend toward increased mortality rate in the high-clinical/high-ST-risk group. For the composite end point, ST subgrouping resulted in significant event stratification in both patients at low and high clinical risk. In multivariable analysis, age and heart rate were independent predictors of both mortality and the composite end point. Late ST elevation added incremental prognostic information.

CONCLUSION

Age, heart rate, and late ST elevation are powerful, independent predictors of adverse clinical outcome. Continuous monitoring allows noninvasive assessment of the response to therapy. Consequently, this technique will enhance the potential to risk-stratify individual patients in a real-time setting.

A Bayesian approach to aid in formulary decision making: incorporating institution-specific cost-effectiveness data with clinical trial results

Pharmacy and therapeutics committees commonly cite a lack of generalizability as a reason for not incorporating cost-effectiveness information into decision making. To address this concern, many committees undertake site-specific economic evaluations, which are often limited by small sample sizes and nonrandomized designs. We show how 2 complementary approaches were used to minimize these limitations in an economic evaluation of abciximab at 1 institution. Using a propensity score methodology, we selected patients who did not receive abciximab for the comparison cohort. Then, we adopted a Bayesian, hierarchical, random-effects model to integrate site-specific and clinical trial data. We applied the posterior distributions of effectiveness with local cost data in a traditional decision-analytic model. In 74% of the simulations, abciximab was cost-effective at 1 institution at the $50,000 per life year saved threshold, assuming a 50:50 split of patients undergoing coronary stenting and angioplasty. Among patients undergoing coronary stenting, the cost-effectiveness ratio of the addition of abciximab was at or below the $50,000 per life year saved threshold in 66.0% of the simulations.

An independently derived and validated predictive model for selecting patients with myocardial infarction who are likely to benefit from tissue plasminogen activator compared with streptokinase

BACKGROUND

In the Global Utilization of Streptokinase and tPA for Occluded coronary arteries (GUSTO) trial, patients with myocardial infarction who were treated with tissue plasminogen activator (tPA) had a 6.3% 30-day mortality, compared with a mortality of 7.3% among those treated with streptokinase, despite a greater risk of intracranial hemorrhage with tPA. However, in part because of its higher cost, tPA has not been adopted universally.

METHODS

Using an independently developed model, we predicted the benefits of tPA therapy in the 24,146 patients in the GUSTO trial and compared these predictions with the actual benefits of tPA, after classifying patients by their risks of mortality and intracranial hemorrhage. We also performed a "patient-specific" cost-effectiveness analysis among different strata of expected benefit of tPA.

RESULTS

Our model predicted that among patients with myocardial infarction, 61% of the benefit of tPA use in reducing mortality accrued to only 25% of patients; treating half of patients could capture 85% of the benefit. Including the risk of intracranial hemorrhage, our model predicted that treating half the GUSTO patients with tPA and the others with streptokinase would yield similar outcomes as treating all patients with tPA, because the additional risk of intracranial hemorrhage exceeded the expected benefit in some patients. When patients were stratified into quartiles of risk, the observed outcomes in the GUSTO patients corresponded well with these predicted results. The estimated cost-effectiveness of tPA was sensitive to patient characteristics.

CONCLUSION

For selected patients, use of tPA yields substantially better outcomes than streptokinase, and use of the less expensive agent is difficult to justify. For many patients, however, tPA is unlikely to provide any additional benefit and, in some patients, it may even cause net harm.

Very early assessment of risk for in-hospital death among 11,483 patients with acute myocardial infarction. GISSI investigators

BACKGROUND

The efficacy of reperfusion therapy after acute myocardial infarction is time dependent. The risk profile of every patient should be available as soon as possible. Our aim was to determine whether collection of simple clinical markers at hospital admission might allow reliable risk stratification for in-hospital mortality.

METHODS

The subjects were 11,483 patients with acute myocardial infarction from the GISSI-2 cohort. The GISSI-1 and GISSI-3 populations were selected to validate the classification. To stratify patients, the tree-growing method called recursive partitioning and amalgamation (RECPAM) was used. This method is used to identify homogeneous and distinct subgroups with respect to outcome.

RESULTS

The RECPAM algorithm provided 6 classes. RECPAM class I included Killip class 3 to class 4 patients (516 deaths/1000). RECPAM class II included Killip 2 patients older than 66 years and with anterior infarction or sites of infarction that could not be evaluated (314 deaths/1000). Killip 1 patients older than 75 years and with anterior or multiple sites or sites that could not be evaluated were included in RECPAM class III with Killip class 2 patients younger than 66 years and with systolic blood pressure less than 120 mm Hg or older than 66 years and with any other infarction site (207 deaths/1000). The other classes showed lower mortality rates (91, 32, and 12 deaths/1000 for RECPAM classes IV, V, and VI). In the GISSI 1 and GISSI 3 samples the 6 classes ranked in the same order in terms of mortality rate. With respect to low-risk strata, patients belonging to RECPAM class VI without serious clinical events in the first 4 days had a very low incidence of in-hospital death (0.9%) or morbidity. Cumulative 6-month mortality for the 6 RECPAM classes was 59.6%, 41.2%, 26.4%, 12.9%, 4. 8%, and 2.2%.

CONCLUSIONS

Four simple clinical markers readily available at admission of patients with myocardial infarction allow a quick, reliable, and inexpensive prediction of risk for in-hospital and 6-month mortality. The RECPAM classification also helped identify a large subgroup of patients fit for early hospital discharge.

The magnitude of the benefit from preCCU thrombolysis in acute myocardial infarction: a long term follow up

OBJECTIVE

Our aim was to determine the relationship among the time saved by administration of thrombolytic therapy in prehospital versus hospital setting and long term mortality; number, duration of hospitalizations and their causes.

BACKGROUND

There is much theoretic, experimental and trial evidence to indicate that in acute myocardial infarction the earlier the thrombolytic therapy is given, the greater its efficacy. However, the clinical importance of this gain time in long term is still uncertain.

SUBJECTS

280 patients with suspected acute myocardial infarction in perspective, controlled study with two parallel groups of consecutive patients without contraindication for thrombolysis, who were seen by general emergency physicians before hospitalization (Gr.1) or later in hospital by the attending cardiologist (Gr.2). The main outcomes measured was mortality rate at 5 years, causes, number and duration of new hospitalizations.

RESULTS

The median pain to needle time was 90' (25 degrees percentile:67'; 75 degrees percentile:165') in Gr.1 vs 165' in Gr.2 (25 degrees percentile:110'; 75 degrees percentile:225'). The median time difference was 75' (P<0.001). The 35th day total mortality rate was 7.5% and 10.6% (p:n.s.) in Gr.1 vs Gr.2 respectively, 8.6% (Gr.1) vs 19.7% (Gr.2) (P<0.015) at 1 year, and 19.2% (Gr.1) vs 47.2% (Gr.2) (P<0.015) at 5 years. The percentage of patients with a number of new hospitalizations greater than 1 during 5 years was not significantly different in Gr.1 vs Gr.2 (44.1% vs 48.35, p:n.s.). The total duration of hospitalization was 479 days in Gr.1 vs 1431 days in Gr.2 (P<0.001). The 75 Gr.1 patients alive at the end of 5 years follow up had a mean hospital stay of 3.86+/-5.92 days vs 8.05+/-16.60 days (P<0.036) of the 94 Gr.2 patients alive after 5 years. The total and mean stay for recurrence of acute MI was significantly different in Gr.1 vs Gr.2 (90 vs 425 days: P<0.001; and 13+/-6.2 days vs 25+/-5.4: P<0.003 respectively). Cardiac failure led to the 1.16% in Gr.1 vs 9.43% of new admission (P<0.028) for a total of 57 vs 243 days in Gr.1 and Gr.2 respectively (P<0.001). Cumulative mortality rate for any cause at 5 years was 19.2% and 47.2% in prehospital and in hospital treated patients (P<0.015), obtaining diverging survival curves.

CONCLUSIONS

The magnitude of the benefit from earlier thrombolysis is such that giving thrombolytic treatment earlier is the main problem to reduce the time from onset of symptoms to reperfusion, to salvage myocardial muscle and obtain diverging survival curves.

Treatment of acute myocardial infarction today

The management of acute myocardial infarction (AMI) has undergone major changes in the last decade. Today clinical practice can be based on sound evidence derived from a large number of well-conducted, randomized, large-scale clinical trials. Because of this, Scientific Societies, such as the European Society of Cardiology, have recently produced evidence-based guidelines for the treatment of AMI. This article summarizes the up-to-date, evidence-based treatments for patients with AMI, and their limitations in terms of uncertainty and transferability to real populations.

Selection of thrombolytic therapy for individual patients: development of a clinical model. GUSTO-I Investigators

We developed a logistic regression model with data from the GUSTO-I trial to predict mortality rate differences in individual patients who received accelerated tissue plasminogen activator (TPA) versus streptokinase treatment for acute myocardial infarction. A nomogram was developed from a reduced version of this model that approximated the underlying risk of patients treated with streptokinase, and thus the benefit of TPA. The 30-day mortality rate with accelerated TPA was 0.063 versus 0.073 with streptokinase and subcutaneously administered heparin and 0.074 with streptokinase and intravenously administered heparin. No baseline patient characteristics were significantly associated with a different relative effect of TPA. Older patients and those with anterior infarction, higher Killip classification (except Killip class IV), lower blood pressure, and increased heart rate had the greatest absolute benefit with accelerated TPA. Patients with acute myocardial infarction who had more high-risk characteristics derived a greater absolute benefit from treatment with accelerated TPA versus streptokinase.

Implications of the GUSTO trial for thrombolytic therapy

This article discusses the impact of previous clinical observations on the development of the GUSTO-I protocol, particularly the absence of a survival benefit of alteplase (rt-PA) over streptokinase in the GISSI-2/International Study Group and ISIS-3 trials in spite of a higher efficacy for clot lysis. The demonstrated superiority of front-loaded alteplase in this large trial is translated into useful guidelines for the practising clinician. Risk-benefit analysis indicates that, in general, this thrombolytic regimen is most indicated in patients presenting with large amounts of jeopardized ischaemic myocardium in the absence of a particularly increased risk of haemorrhagic stroke. Finally, the impact of this study for future development in the field of acute coronary syndromes is evaluated, more specifically for the design of new trials with new fibrinolytic and antithrombotic agents. These include mutants of alteplase, staphylokinase, direct antithrombins and inhibitors of the glycoprotein IIb/IIIa platelet receptor.