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BOSTON -- Carvedilol (Coreg, Coreg CR) helped to mitigate cardiac risk in patients undergoing pheochromocytoma surgery, researchers reported here.

In a comparison of several blood pressure (BP) medications, carvedilol was the only medication found to lower the odds of cardiac complications following surgery to remove pheochromocytoma after adjustment for average preoperative heart rate and systolic blood pressure (OR 0.04, 95% CI 0.003-0.0751, P=0.034), reported Rami Alrezk, MD, of the NIH Section of Medical Neuroendocrinology in Bethesda, Maryland, and colleagues.

The other BP medications were metoprolol (Lopressor, Toprol XL), atenolol (Tenormin), phenoxybenzamine (Dibenzyline) and amlodipine (Norvasc).

This outcome held true after further adjustment for congestive heart failure (OR 0.013, 95% CI 0.00051-0.37114, P=0.01), they reported at the American Association of Clinical Endocrinologists (AACE) annual meeting.

Other medications, including phenoxybenzamine (OR 8.5, 95% CI 0.7- 102, P=0.09), were not associated with any cardio-protective properties in pheochromocytoma surgery, the authors stated.

The good balance of combination alpha and beta blockade in this drug may be one explanation for this finding, Alrezk told MedPage Today, adding carvedilol "could have properties that is beyond its ability of controlling the heart rate and blood pressure."

Moreover, similar protective findings for carvedilol (OR 0.01, 95% CI 0.0003-0.2958, P=0.0074) were reported even after further adjustment for coronary artery disease, not seen in other medications, such as phenoxybenzamine (OR 8.5, 95% CI 0.7-102, P=0.09).

"All surgeries have inherent cardiac risk associated with the stress of surgery and anesthesia, but pheochromocytoma surgery has a greater cardiac risk," Alrezk explained, adding how these tumors often are biochemically active and produce catecholamines, including epinephrine and norepinephrine, which place the heart at additional risk.

The analysis included data on 310 patients who underwent surgical resection for pheochromocytoma and paraganglioma at the NIH. The primary composite outcome of the study included occurrence of NU, cardiac arrest, congestive heart failure, pulmonary edema, ventricular tachycardia, ventricular fibrillation, respiratory failure, Presser use, or death after surgery while still in the hospital.

In total, less than 4% of the sample experienced a cardiac complication (seven males and five females).

In another analysis of the same group of pheochromocytoma patients presented at AACE, the authors reported that an average heart rate >90 was independently linked to a higher perioperative cardiac risk (OR 7.29, 95% CI 1.18-44.6, P=0.0318). Additionally, African-American patients had an elevated incidence of experiencing a cardiac event (8%, X²=27.1, P=0.001).

Although additional research is needed, Alrezk recommended clinicians "consider starting with low dose carvedilol when blockade is indicated, and titrating the dose up as tolerated and in accordance with the guidelines. There, carvedilol can be considered as initial alpha and beta blockade medication."

However, he added that "it could be difficult in some circumstances to achieve optimal heart rate control or optimize blood pressure with this agent if maximal dose was achieved," adding that this could occur with metastatic pheochromocytoma.

"In such a scenario, additional blockade is necessary but needs to be done by experienced hands, especially if considering adding additional beta blocker" he stated.