Effect of Early revascularization versus delayed revascularization versus medical therapy on inpatient mortality in patients with non ST elevation MI in a community hospital Setting

Owais Jeelani ,MBBS Mentor:Dr.A.Herle,MD,FACC

Background

• Coronary heart disease is the leading cause of death in the United States, with myocardial infarction a common manifestation of this disease.

• Of all patients having a myocardial infarction, 25 to 35% die before receiving medical attention, most often from ventricular fibrillation. For those who reach a medical facility, the prognosis is considerably better and has improved over the years: in-hospital mortality rates fell from 11.2% in 1990 to 9.4% in 1999

Background

• In 2006, approximately 1.2 million Americans

sustained a myocardial infarction. Of these, two third had a myocardial infarction without ST-segment elevation

Background

• Randomized trials have shown that a routine invasive strategy is beneficial in high-risk patients with acute coronary syndromes.

Non-ST Elevation ACSNon-ST Elevation ACS

Generally caused by partially occlusive,

platelet-rich thrombus

Unobstructedlumen

thrombus

Results from cross-linking of fibrinogen by platelet GP IIb-

IIIa receptors at sites of plaque rupture

platelet

fibrinogen

Rupturedplaque

GP IIb-IIIa

Artery wall

Background

• In patients with myocardial infarction with ST-segment elevation, in which the infarct-related artery is usually occluded and there is ongoing transmural ischemia, it is well established that the earlier primary percutaneous coronary intervention can be performed, the lower the mortality.

• By contrast, in patients with acute coronary syndromes without ST-segment elevation (including unstable angina and myocardial infarction), the culprit artery is often patent, there is usually no ongoing transmural ischemia, and the patient may have a good response to initial medical treatment.

Background

• Although meta-analyses of previous randomized trials that compared an invasive strategy with a conservative strategy in patients

with acute coronary syndromes have shown a benefit for an invasive strategy, the timing of angiography in the invasive-strategy group of these previous studies ranged from as early as 19 hours after randomization in one large trial to as late as 96 hours in another large trial.

Invasive vs. Conservative Strategy for UA/NSTEMI – All Studies

TIMI IIIBTIMI IIIB

Conservative Invasive

VANQWISHVANQWISHMATEMATE

FRISC IIFRISC II

TACTICS-TIMI 18

TACTICS-TIMI 18

VINOVINO

RITA-3RITA-3

# Pts: 1140 1674 7018

TRUCS TRUCS

ISAR-COOL ISAR-COOL

ICTUSICTUS

Background

• Given this wide variation in the timing, there remains substantial uncertainty regarding the optimal timing for intervention in such patients.

• Small, randomized trials comparing early intervention with delayed intervention have generated conflicting results.

Background

• Although some observational analyses have suggested that earlier intervention, as compared

with delayed intervention, may reduce events, others have suggested that outcomes appear to be similar between the two approaches.

• Also, there has been a suggestion of a hazard

associated with routine early intervention.

Study Objective

• Primary endpoint:

-Is early revascularization better than delayed revascularization or Medical therapy alone in reducing in hospital mortality in Patients with non ST elevation MI in a community care setting?

Secondary endpoint

• What is the relative mortality of NSTEMI patients undergoing early revascularization vs delayed revascularization vs medical therapy alone?

• What is the relative length of hospital stay in the three groups studied?

• What percentage of coronary angiography patients actually underwent intervention (PCI or CABG)?

Methods

• Retrospective Data Analysis of patients at Mercy Hospital who have documented non ST elevation MI from June 2008 to June 2009

• Institutional Review Board approval through the Catholic Health System

• 383 out of 591 patients reviewed were enrolled in the study after meeting the inclusion criteria

Inclusion criteria

• Based on ICD Coding 410.71• Patients with non ST elevation MI with chest

pain at rest, lasting > 30 minutes and non-responding to sublingual nitroglycerin tablets in addition to elevated troponins greater than or equal to 0.1.

Exclusion criteria

• Patients with ST elevation MI not fulfilling the above criteria.

• Patients with MI not fulfilling the above inclusion criteria

Analysis of Data

• Mortality odds ratios used for the comparison of proportion of deaths in each arm (primary end point).

• Length of Stay comparison evaluated by mean number of days along with 95% confidence interval standard deviations.

• paired t-test with a p-value of <0.05 deemed statistically significant

Results• Primary End-Point– There is statistically significant difference in in-

hospital mortality between patients treated with revascularization versus patients treated conservatively.

– This difference is reflected in patients >65 yrs of age.

– There is no statistically significant difference in in-hospital mortality in patients younger than 65 yrs.

– There is statistically significant difference in in-hospital mortality in males, patients with ischemic changes on EKG and patients having more than 3 risk factors.

Results

• Primary End-Point -No statistically significant difference in in-hospital

mortality in patients treated with early revascularization versus patients treated with delayed vascularization

Results

• Secondary Outcome– Statistically significant difference in hospital length

of stay in patients treated with re vascularization versus patients treated conservatively

– Statistically significant difference in hospital length of stay in patients treated with early revascularization versus patients treated with delayed revascularization.

– Statistically significant difference in hospital length of stay in patients >65 years treated with revascularization versus patients treated conservatively.

Conclusion

Revascularization offers benefit in reducing short term mortality over medical therapy alone

Benefit is more pronounced in elderly high risk male patients.

Immediate catheterization and intervention does not offer a benefit over initial medical stabilization followed by delayed catheterization and intervention

How are we doing?

• Comparison with Action registry data

Thinking outside the box…

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