# Ambulatory blood pressure monitoring before and after resection of catecholamine-secreting pheochromocytoma or paraganglioma

## TL;DR

Removing catecholamine-secreting tumors lowers blood pressure and improves its variability, especially at night, but some patients still have hidden high blood pressure.

## Contribution

This study provides empirical evidence on blood pressure changes after tumor resection using ambulatory monitoring.

## Key findings

- Blood pressure and variability significantly improved after tumor resection, especially during nighttime.
- Controlled hypertension increased from 12% to 32% post-surgery.
- Masked hypertension remained unchanged, suggesting residual cardiovascular risk in some patients.

## Abstract

Pheochromocytomas/paragangliomas are catecholamine-secreting tumors that are a rare cause of hypertension and associated with high cardiovascular risk. We aimed to evaluate changes in 24-h ambulatory blood pressure (BP) monitoring (ABPM) following tumor resection. Individuals with evidence of pheochromocytoma/paraganglioma prospectively underwent 24-h ABPM and plasma and urine catecholamine measurement 2–3 weeks before and 6–8 weeks after pathologically-confirmed tumor resection. Patients with metastatic disease were excluded. Changes in office, 24-h, daytime, and nighttime mean systolic and diastolic BP and heart rate, 24-h BP and heart rate average real variability, and rates of controlled, sustained, white coat, and masked hypertension were assessed in paired analyses. There were 34 participants who completed 24-h ABPM before and after tumor resection. Mean age was 55 ± 13 years, with 21 (62%) women, median duration of hypertension of 3 years, and 6 (18%) participants with coronary artery disease. Serum and urine catecholamines normalized following tumor resection and participants were prescribed 1 ± 0.2 fewer antihypertensive medications. Office BP declined by a mean 10 ± 16/7 ± 9 mmHg, 24-h BP declined by 8 ± 14/4 ± 10 mmHg, with greater improvement in nighttime (9 ± 18/5 ± 13 mmHg) than daytime (7 ± 14/4 ± 9) ambulatory BP. Systolic BP variability and heart rate variability significantly improved. While the frequency of controlled hypertension increased (4 [12%] to 11 [32%]; p = 0.008), there was no significant change in masked hypertension (9 [26%] to 12 [35%]; p = 0.366). In conclusion, pheochromocytoma/paraganglioma resection was associated with improvement in 24-h BP and BP variability, particularly nighttime BP. ABPM may be useful following tumor resection to identify patients with unrecognized residual cardiovascular risk.