Importance of thorough investigation of resistant hypertension before renal denervation: should compliance to treatment be evaluated systematically?

Catheter-based renal denervation (RD) has been introduced recently as a potentially effective invasive treatment of refractory hypertension. The proportion of patients with severe hypertension suitable for RD is not clear. The aim of this study was to identify what percentage of patients has truly resistant essential hypertension and are thus potentially eligible for RD. We investigated 205 consecutive patients referred to a university hypertension center for severe hypertension within 12 months. Ambulatory 24-h blood pressure (BP) monitoring (24 h ABPM), secondary hypertension screening and compliance to treatment testing (by use of plasma drug level measurements) were performed in all patients. Fifty-seven patients (27.8%) did not have truly resistant hypertension (RH) based on clinical BP. Among the remaining 122 patients (59.5%) with RH confirmed by 24 h ABPM, 50 patients (24.4% of the original cohort) had a secondary cause of hypertension and in 27 (13.2%) non-compliance to treatment was confirmed. Thus, only 45 patients (22%) had truly resistant essential hypertension and were considered for RD. Only one-third (n=15, 7.3% of the original cohort) was, however, finally referred for RD (14 were excluded due to contraindications for RD and 16 refused the invasive treatment). In conclusion, thorough examination of severe hypertension including 24 h ABPM, secondary hypertension exclusion and drug compliance testing before considering RD reveals that majority of these patients are not suitable for RD. Specifically, compliance to treatment testing should be mandatory in order to identify eligible candidates for RD.

Peripheral arterial stiffness in primary aldosteronism.

Aldosterone overproduction increases arterial wall stiffness by accumulation of different types of collagen fibres and growth factors. Our previous studies showed that central (aortic) arterial stiffness is increased in primary aldosteronism (PA) independently of concomitant hypertension and that these changes might be reversible after successful adrenalectomy. There is limited data available on the potential impact of mineralocorticoid overproduction on the deterioration of peripheral arterial stiffness. The current study was thus aimed at investigating the effect of aldosterone overproduction on peripheral arterial stiffness assessed by peripheral (femoral-ankle) pulse wave velocity (PWV) in PA patients compared with essential hypertension (EH) patients. Forty-nine patients with confirmed PA and 49 patients with EH were matched for age, blood pressure, body mass index, lipid profile, and fasting glucose. PWV was obtained using the Sphygmocor applanation tonometer. Both peripheral and central PWV were significantly higher in PA patients compared to EH patients, while clinical blood pressures were similar. Plasma aldosterone level was the main predictor of peripheral PWV in PA. Our data indicate aldosterone overproduction in PA does not preferentially affect central arterial system. Fibroproliferative effect of higher aldosterone levels lead to alteration of central-elastic as well as peripheral-muscular arteries with subsequent increase in its stiffness.

Inferior vena cava (IVC) filter thrombosis in a renal transplant recipient.

We report a renal transplant patient with a functioning allograft who had an inferior vena cava (IVC) filter placed above the renal allograft vein. The patient occluded the IVC filter and developed extensive distal thrombosis. This included complete occlusion of the renal allograft vein (RAV). However, this complication did not lead to a loss of kidney transplant function. Alternate allograft venous drainage via capsular collaterals and subsequent recanalization of transplant vein were demonstrated.