The Multicenter Diltiazem Post Infarction Trial - MDPIT

Description:

Diltiazem for mortality and cardiac events after MI.

Hypothesis:

Diltiazem improves mortality and decreases cardiac events when given to patients following myocardial infarction.

Study Design

Study Design:

Patients Screened: Not given
Patients Enrolled: 2,466
NYHA Class: II/I=(19%)
Mean Follow Up: 25 months (12-52 months)
Mean Patient Age: 58
Female: 20
Mean Ejection Fraction: 46%

Patient Populations:

Documented acute myocardial infarction; 25-75 years old

Exclusions:

Cardiogenic shock or symptomatic hypotension
Pulmonary hypertension with right ventricular failure
Sinus bradycardia (< 50 beats/minute)
High grade AV block
Other condition requiring calcium channel blocker
ECG with QRS > 180 msec or Qtc > 500 msec

Primary Endpoints:

Mortality (total)
Death from cardiac causes
Nonfatal myocardial infarction

Secondary Endpoints:

Primary endpoints combined

Drug/Procedures Used:

Diltiazem (60mg BID - QID)
Baseline chest x-ray (to identify pulmonary congestion)
Radionuclide ejection fraction (42%)
24 hour Holter monitor (68%)

Concomitant Medications:

Antiarrhythmic drugs (9%)
Beta blockers (54%)
Digitalis (14%)
Diuretics (23%)
Nitrates (60%)

Principal Findings:

No difference between groups in total mortality.

11% fewer first recurrent cardiac events (cardiac death or nonfatal reinfarction with diltiazem than placebo but not statistically significant).

Increased AV block, bradycardia and hypotension in diltiazem group.

More cardiac events with diltiazem in patients with left ventricular dysfunction.

When ejection fraction < 40% late congestive heart failure appeared in 12% receiving placebo and 21% on diltiazem (p = 0.004).

Patients with pulmonary congestion, anterolateral Q wave infarction, or reduced ejection fraction (EF) at baseline were more likely to have CHF during follow-up than those without these markers of LV dysfunction.

Interpretation:

"Data demonstrates that diltiazem treatment is not appropriate for all patients after myocardial infarction. There is strong evidence of favorable or unfavorable outcome, depending on the presence or absence of left ventricular dysfunction." (From Manuscript)

These data are further supported from results of a secondary analysis of MDPIT data identifying increased risk of congestive heart failure in patients with reduced ejection fraction after myocardial infarction treated with diltiazem. Circulation 1991;83:52-60.

References:

1. N Engl J Med 1988;319:385-392. Final results
2. Circulation 1991;83(1):52-60. LV dysfunction subgroup

Clinical Topics: Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Implantable Devices, EP Basic Science, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Acute Heart Failure

Keywords: Diltiazem, Atrioventricular Block, Myocardial Infarction, Follow-Up Studies, Radioisotopes, X-Rays, Heart Failure, Hypotension, Electrocardiography, Ambulatory, Ventricular Dysfunction, Left, Calcium Channel Blockers


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