Preoperative first-line amlodipine in phaeochromocytoma/paraganglioma: perioperative haemodynamic instability and its predictors.

OBJECTIVES

Preoperative alpha blockade is recommended for phaeochromocytomas and paragangliomas (PPGLs), whereas evidence for calcium channel blockers remains limited. This study evaluated perioperative haemodynamic outcomes with first-line amlodipine for preoperative blockade and identified predictors of intraoperative haemodynamic instability (iHDI).

METHODS/

DESIGN

In this monocentric retrospective study, 35 operated PPGL patients who received preoperative first-line amlodipine (July 2021-March 2024) were analysed. Continuous intraoperative arterial pressure recordings were analysed for episodes and duration of hypertension, hypotension, and iHDI. Biochemical phenotype and tumour characteristics were assessed as predictors.

RESULTS

The cohort (median age: 32 years; 60% female) included 32 phaeochromocytomas and 3 sympathetic paragangliomas. Germline variants were detected in 20/34 tested patients (cluster 1: 11; cluster 2: 9). Amlodipine up to 20 mg was tolerated in all except two, with a median of 7 days to reach BP targets. Median iHDI duration was 6.67% (0-16.4). On linear regression, log-transformed plasma free metanephrine (PFMN) independently predicted iHDI duration (β = 2.26, P = 0.027). Patients with adrenergic phenotype (n = 13) exhibited a longer duration of SBP ≥ 160 mmHg (14 vs 1 min), a higher peak SBP (201 vs 160 mmHg), and a higher nitroglycerine dose (659 vs 59.6 μg) than those with noradrenergic phenotype. Postoperative hypotension (37.1%) was associated with a higher plasma free normetanephrine level (3,440 vs 1,242.9 ng/L) and a larger tumour size (5.1 vs 4.2 cm). No perioperative mortality occurred.

CONCLUSION

First-line amlodipine blockade was effective in preventing iHDI in PPGLs. Plasma free metanephrine and normetanephrine correlated with intraoperative hypertension and postoperative hypotension, respectively.