Factors Associated with Normal Blood Pressure after Surgery To Treat Primary Aldosteronism

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The summary below is from the full report titled "Primary Aldosteronism: Factors Associated with Normalization of Blood Pressure after Surgery." It is in the 21 August 2001 issue of Annals of Internal Medicine (volume 135, pages 258-261). The authors are AM Sawka, WF Young Jr., GB Thompson, CS Grant, DR Farley, C Leibson, and JA van Heerden.

What is the problem and what is known about it so far?

The adrenal glands are small organs located near the kidneys. The adrenal glands make several hormones, including aldosterone, which helps to regulate blood pressure and kidney function. Adenomas are noncancerous tumors that can develop in the adrenal glands. These tumors produce abnormally high amounts of the hormone aldosterone (hyperaldosteronism), a condition known as primary aldosteronism. Among other things, people with primary aldosteronism develop high blood pressure. Surgery to remove the adrenal gland that has the adenoma cures between 30% and 60% of cases of primary aldosteronism. It is difficult to predict which patients will be cured by this surgery.

Why did the researchers do this particular study?

To determine factors associated with cure of primary hyperaldosteronism after surgery to remove the affected adrenal gland.

Who was studied?

97 patients with primary aldosteronism who had surgery to remove an adrenal gland at the Mayo Clinic in Rochester, Minnesota, between January 1993 and December 1999.

How was the study done?

The researchers collected information from the patients' medical records—including age, sex, medical history, blood pressure before and after surgery, details of the surgical procedure, use of medications to treat high blood pressure, and aldosterone levels. They then compared the characteristics of patients who had normal blood pressure after surgery with those of patients whose blood pressure remained high.

What did the researchers find?

Blood pressure became normal after surgery in 31 of the 94 patients. Cure of high blood pressure was more likely for patients who had no more than one first-degree relative with a history of high blood pressure and who needed no more than two blood pressure medications to control blood pressure before surgery.

What were the limitations of the study?

This study relied on information in the medical records rather than having the researchers collect the needed information at the time the patients were receiving care. Information in medical records can be incomplete. In addition, patients had their blood pressure measured at different time points after surgery, so this study does not tell us how long it takes for blood pressure to become normal after surgery.

What are the implications of the study?

Patients with primary hyperaldosteronism are more likely to have normal blood pressure after surgery if they have no more than one first-degree relative with a history of high blood pressure and if they needed no more than two blood pressure medications to control blood pressure before surgery.