Journal Scan: Does pimobendan prevent CHF or sudden death in Dobermans with preclinical DCM?

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Why they did it

About 25% to 50% of purebred Doberman pinschers eventually develop dilated cardiomyopathy (DCM).1,2 Can this positive inotrope help delay the progression and extend lives?

What they did

As part of a multicenter, blinded, placebo-controlled trial, researchers enrolled 76 Doberman pinschers with echocardiographic evidence of preclinical DCM based on weight-adjusted values of left ventricular internal dimension in systole. Dogs were recruited between July 2006 and December 2010. A Holter recording was also performed on all dogs to ensure no dog had sustained ventricular tachycardia.

Dogs were randomized to receive either pimobendan (median dose 0.453 mg/kg/day) or placebo in a 1:1 ratio. A Holter recording was repeated after initiation of the test medication. The primary endpoint evaluated was either the onset of congestive heart failure (CHF) or sudden death. Cardiac death was assumed if no other apparent cause of death was found.

What they found

Dogs in the pimobendan group reached the primary endpoint much later than those receiving placebo (718 days vs. 441 days, respectively), although the proportion of dogs reaching each component of the primary endpoint was similar between the two groups. Median survival time was also significantly longer (P = 0.034) among those in the pimobendan group (623 days) compared with those in the placebo group (466 days). Dogs with higher heart rates on physical examination as well as those with evidence of ≥ 4 ventricular premature complexes on a three-minute ECG were seven times more likely to reach the primary endpoint first after adjusting for the effect of treatment.

Take-home message

Pimobendan given to Dobermans with preclinical DCM delays onset of clinical signs and extends survival.

REFERENCES

1. Wess G, Schulze A, Butz V, et al. Prevalence of dilated cardiomyopathy in Doberman Pinschers in various age groups. J Vet Intern Med 2010;24:533-538.

2. O’Grady MR, O’Sullivan ML. Dilated cardiomyopathy: an update. Vet Clin North Am Small Anim Pract 2004;34:1187-1207.

Summerfield NJ, Boswood A, O’Grady MR, et al. Efficacy of pimobendan in the prevention of congestive heart failure or sudden death in Doberman Pinschers with preclinical dilated cardiomyopathy (The PROTECT study). J Vet Intern Med. 2012;26(6):1337-1349.

Link to full text: http://onlinelibrary.wiley.com/doi/10.1111/j.1939-1676.2012.01026.x/full