What question did this study set out to answer?

To evaluate the acute and chronic haemodynamic and clinical effects of oral prazosin during rest and exercise in patients with severe congestive cardiac failure.

July 1, 1980The Medical Journal of Australia

The Acute and Chronic Haemodynamic Effects of Prazosin in Severe Congestive Cardiac Failure

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Why the study?

Does prazosin improve haemodynamics in patients with severe congestive cardiac failure?

Population

16 patients with severe congestive cardiac failure

Comparison

Prazosin vs Placebo (four-week period in a crossover design)

Design

RCT, double-blind

Follow-up

8 weeks (two 4-week periods)

Authors

RHRichard W. HarperMemorial Sloan Kettering Cancer Center HCHeather ClaxtonThe Alfred Hospital KMKen MiddlebrookThe University of Sydney

Discussion

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Implication

Acute prazosin benefits in severe HF attenuate with chronic use; challenges sustained efficacy assumptions and supports dedicated outcome trials.

Key Points

To evaluate the acute and chronic haemodynamic and clinical effects of oral prazosin during rest and exercise in patients with severe congestive cardiac failure.
Assessed acute resting and exercise haemodynamics in 16 hospitalized patients with severe congestive cardiac failure after an oral dose of prazosin (3 to 5 mg).
Conducted a chronic outpatient double-blind crossover trial comparing 4 weeks of prazosin with 4 weeks of placebo in patients on stable digoxin and diuretic therapy (N=12 enrolled, N=9 completed).
Acute prazosin administration significantly reduced resting and exercise left ventricular filling pressure, increased resting cardiac index, reduced resting mean arterial pressure, and improved exercise duration without altering heart rate.
Chronic 4-week prazosin therapy produced less marked haemodynamic effects, causing a fall in resting mean arterial pressure, a minor decline in resting left ventricular filling pressure, and an increase in exercise cardiac index.
Chronic prazosin did not significantly alter resting cardiac index, exercise duration, exercise left ventricular filling pressure, or resting and exercise heart rates compared to placebo, with only 2 of 9 patients reporting symptomatic improvement.

Structured PICO

Does prazosin improve haemodynamics in patients with severe congestive cardiac failure?

Population

16 patients with severe congestive cardiac failure

Intervention

Prazosin (3 to 5 mg oral dose acutely, then four weeks' chronic therapy)

Comparator

Placebo (four-week period in a crossover design)

Outcome

Haemodynamic parameters (left ventricular filling pressure, cardiac index, mean arterial pressure, heart rate) at rest and during exercisesurrogate

Prazosin produces marked acute haemodynamic benefits in severe heart failure, but these effects attenuate during chronic therapy.

Cite This Study

Harper et al. (1980) studied this question.

synapsesocial.com/papers/6a72a51af44fa9f079e00bf6 https://doi.org/10.5694/j.1326-5377.1980.tb125810.x

Topics

Heart failure HFrEF treatment

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Implication

Acute prazosin benefits in severe HF attenuate with chronic use; challenges sustained efficacy assumptions and supports dedicated outcome trials.

The Acute and Chronic Haemodynamic Effects of Prazosin in Severe Congestive Cardiac Failure

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Topics

The Acute and Chronic Haemodynamic Effects of Prazosin in Severe Congestive Cardiac Failure

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Topics

Also Consider