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Rescue Angioplasty vs Repeat Thrombolysis in Acute MI?

 

In patients with failed primary thrombolysis following an acute MI, when compared with non-PCI management (pooled results of conservative management & repeat thrombolysis), PCI reduces cardiac and cerebral events (NNT=12) and “all-cause” mortality (NNT = 16).   However, when compared directly with either conservative management OR repeat thrombolysis there was no mortality benefit. 

Level of Evidence: 1+ (RCT with a low risk of bias)

 

Citation: Gershlick AH, Stephens-Lloyd A, Hughes S et al for the REACT Trial Investigators. Rescue angioplasty after failed thrombolytic therapy for acute myocardial infarction. N Engl J Med 2005; 353: 2758-68


Lead author's name and email: Anthony Gershlick, agershlick@aol.com

 

Three-part Clinical Question:

Patients: Suffering from an acute ST elevation myocardial infarction that failed to show >50% resolution of ST segment elevation within 90 minutes of receiving thrombolysis.

Treatment: Percutaneous Intervention (PCI) vs. Repeat Thrombolysis vs. Conservative Management

Outcomes: Primary = Composite of cardiac and cerebrovascular events (all cause mortality, cardiac mortality, recurrent myocardial infarction, cerebrovascular event and severe heart failure). Secondary = risk of major and minor bleeding and need for revascularisation.
Search Terms: Myocardial infarction, management, PCI, thrombolysis

 

The Study: Double-blinded concealed randomised controlled trial with intention-to-treat.
The Study Patients: All patients with an acute ST-elevation infarction who received thrombolysis within 6 hours of the onset of chest pain but in whom there had been less than 50% resolution of ST segments 90 minutes after starting thrombolysis. Exclusion criteria included cardiogenic shock, LBBB and a haemoglobin >1.5g/dl below the normal range within the previous 6 hours.


Control group (N = 283; 283 analysed): Conservative management (intravenous heparin titrated to an APTT ratio of 1.5-2.5) or repeat thrombolysis using a fibrin-specific thrombolytic agent plus intravenous heparin.


Experimental group (N = 144; 144 analysed): Coronary angiography, +/- angioplasty, +/- adjuvant therapy (stenting or glycoprotein IIb/IIIa inhibitors) determined at the time of PCI.

 

The Evidence:

 

Outcome

Time to Outcome

CER

EER

RRR

ARR

NNT

Cardiac and Cerebrovascular events

6 months

0.233

0.153

34%

0.080

12

95% Confidence Intervals:

1% to 67%

0.003 to 0.157

6 to 303

Mortality (all cause)

6 months

0.127

0.063

50%

0.064

16

95% Confidence Intervals:

7% to 94%

0.009 to 0.119

8 to 118

Mortality (cardiac cause)

6 months

0.102

0.056

45%

0.046

NS

95% Confidence Intervals:

ns

ns

ns

 

Non-Event Outcomes

Time to outcome/s

Control group

Experimental group

P-value

Revascularisation

6 months

22.4% (Conservative)

25.6% (Repeat Thrombolysis)

13.8%

p=0.05

 

Comments:


1) Do the methods allow accurate testing of the hypothesis? Yes 

2) Do the statistical tests correctly test the results to allow differentiation of statistically significant results? Yes 

3) Are conclusions valid in light of the results? Yes-their primary outcome measure was a composite of death, recurrent MI, severe heart failure and cerebrovascular events. 

4) Did results get omitted, and why? Yes. Patients randomized to one arm were allowed to have another treatment if the investigators thought that it was clinically indicated, for instance, due to ongoing chest pain or the development of cardiogenic shock. However, analyzing on an intention-to-treat basis did not change the statistical outcome. 

5) Did they suggest areas of further research? No, although given the trend towards reduced mortality, repeating this study with mortality as the sole primary outcome measure may lead to a positive answer. Unfortunately this trial was stopped early due to problems with recruitment and funding. 

6) Did they make any recommendations based on the results and were they appropriate? Yes. Rescue PCI is indicated in failed thrombolysis. Given that this reduces recurrent MI but not outcome measures such as morbidity or mortality, this needs to be interpreted with caution. 

7) Is the study relevant to my clinical practice? Yes 

8) What level of evidence does this study represent? 1+ (RCT with a low risk of bias) 

9) What grade of recommendation can I make on this result alone? B 

10) What grade of recommendation can I make when this study is considered along with other available evidence? B 

11) Should I change my practice because of these results? Only if all patients who don’t receive adequate reperfusion after thrombolysis go on to receive rescue PCI as routine management. There is insufficient evidence to recommend this at present. Conservative management is as effective as repeat thrombolysis. 

12) Should I audit my current practice because of these results? Yes, although you may have too few patients to come up with any meaningful outcome.

 Appraised by: Stephen Harris, Department of Anaesthesia & Critical Care Medicine, Torbay Hospital, Lawes Bridge, Torquay, DEVON TQ2 7AA.; 14 January 2006

Email: stepharr@hotmail.com

 

Citation: EBM Critical Appraisals. Scottish Intensive Care Society EBM Group. 2006 & JICS 2006 Vol7(2). Harris S. Gershlick AH, Stephens-Lloyd A, Hughes S et al for the REACT Trial Investigators. Rescue angioplasty after failed thrombolytic therapy for acute myocardial infarction. N Engl J Med 2005; 353: 2758-68

 

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Kill or Update By: Jan 2010

 

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