Hypertension and hypertensive cardiomyopathy in patients with a relapse-free history of phaeochromocytoma.

BACKGROUND: In patients with a relapse-free history of phaeochromocytoma/paraganglioma (PCC/PGL), persistent hypertension has been reported, but has not been well characterized. METHODS: In 28 patients [mean age 54·5 (26-81) years] with a relapse-free history of PCC/PGLs, we prospectively analysed resting, supine blood pressure (BP), ambulatory BP, echocardiography, exercise testing, metabolic parameters and retrospectively collected data from the time of diagnosis (baseline). Echocardiographic measures were compared to healthy (n = 28) and hypertensive controls (n = 15). RESULTS: Median follow-up was 6 [1-16] years. Three patients had normal office and ambulatory BP and three patients had only increased office BP. Fifty-four per cent of patients had a blunted circadian rhythm. Comparing normal, hypertensive and PCC/PGL patients, we found significant differences in end-diastolic septal thickness (8·8 ± 0·2, 13·8 ± 0·4, 10·0 ± 0·3 mm, P < 0·05), septal basal thickness (9·0 ± 0·3, 15·9 ± 0·5, 11·2 ± 0·4 mm, P < 0·05) and left ventricular mass (143 ± 8, 255 ± 19, 169 ± 9 g, P < 0·05). In five patients, seven major cardiovascular events were observed. Compared to baseline, no significant difference was found in systolic (140 ± 35 vs 137 ± 18 mmHg) and diastolic (85 ± 18 vs 83 ± 10 mmHg) BP. An increase or a decrease in BP (>10 mmHg) was found in 36% and 39% of patients, respectively. The number of antihypertensive drugs had not changed [1 (0-3) vs 1 (0-4)]. Fewer patients received insulin (1 vs 3) or oral antiglycaemic drugs (2 vs 7). CONCLUSION: Our data indicate that hypertension persists after removal of PCG/PGL in a substantial proportion of patients. Hypertensive heart disease is common, and cardiovascular events are frequent in patients with a history of PCC/PGL.

Measurements of plasma metanephrines by immunoassay vs liquid chromatography with tandem mass spectrometry for diagnosis of pheochromocytoma.

BACKGROUND: Reports conflict concerning measurements of plasma metanephrines (MNs) for diagnosis of pheochromocytomas/paragangliomas (PPGLs) by immunoassays compared with other methods. We aimed to compare the performance of a commercially available enzyme-linked immunoassay (EIA) kit with liquid chromatography-tandem mass spectrometric (LC-MS/MS) measurements of MNs to diagnose PPGLs. METHODS: In a substudy of a prospective, multicenter trial to study the biochemical profiles of monoamine-producing tumors, we included 341 patients (174 males and 167 females) with suspected PPGLs (median age 54 years), of whom 54 had confirmed PPGLs. Plasma MNs were measured by EIA and LC-MS/MS, each in a specialized laboratory. RESULTS: Plasma normetanephrine (NMN) and MN were measured 60 and 39% lower by EIA than by LC-MS/MS. Using upper cut-offs stipulated for the EIA, diagnostic sensitivity was only 74.1% at a specificity of 99.3%. In contrast, use of similar cut-offs for MN and overall lower age-adjusted cut-offs for NMN measured by LC-MS/MS returned a diagnostic sensitivity and specificity of 98.1 and 99.7%. Areas under receiver-operating characteristic curves, nevertheless, indicated comparable diagnostic performance of the EIA (0.993) and LC-MS/MS (0.985). Diagnostic sensitivity for the EIA increased to 96.2% with a minimal loss in specificity (95.1%) following use of cut-offs for the EIA adapted to correct for the negative bias. CONCLUSIONS: The EIA underestimates plasma MNs and diagnostic sensitivity is poor using commonly stipulated cut-offs, resulting in a high risk for missing patients with PPGLs. Correction of this shortcoming can be achieved by appropriately determined cut-offs resulting in comparable diagnostic performance of EIA and LC-MS/MS assays.