NIV Congres

Background Hypertension (HT) in kidney transplant recipients (KTR) may reach prevalence up to 90% and jeopardizes graft and patient survival. The risk for graft loss increases 15% for every 10mmHg systolic BP. Although HT in KTRs is often defined as ≥140/90 mmHg, the KDIGO target for BP in KTRs is <130/80 mmHg. For this purpose KDIGO advises a daily sodium excretion target of 100 mmol. Treatment efficacy of HT in KTRs is largely unknown.With the advent of new, but potentially dangerous approaches to therapy resistant HT such as native sympathetic kidney denervation, insight into treatment efficacy is of vital importance. We evaluated the HT treatment efficacy among Dutch KTR and aimed to identify possibilities for improvement of current therapy.

Methods We retrieved data on office BP and use of antihypertensive drugs (number of medications, dosages not available) from the Dutch Organ Transplant Registration (NOTR) on 6070 KTRs registered in 2011 (55.9% deceased donor; median time since transplantation 7.8 years; 59.4% male; median age 45 years). We also collected data from the 539 KTRs currently cared for at our center, focussing on dosages of antihypertensive drugs and 24h urinary sodium excretion.

Results Average BP in the NOTR registered patients was 134/78 mmHg (SD 18/10). In 40.2% of the NOTR patients BP was≥140/90 mmHg of whom 8.2% used no, 28.5% used one, 34.2% used two and 29.1% used ≥3 antihypertensives. 30.6% had a BP >130/80 but lower than 140/90 mmHg of whom 14.4% used no antihypertensives, 32.8% used one, 32.0% used two and 20.9% used ≥3 antihypertensives. In our center these parameters were comparable, with an average BP of 136/81mmHg (SD 17/10). In 43.4% BP was≥140/90 mmHg of whom 10.2% used none, 25.6% used one, 30.8% used two and 32.9% used ≥3 antihypertensive drugs. 75.3% of the KTRs with BP ≥140/90 mmHg while on ≥3 drugs were prescribed their antihypertensive drugs at dosages that were lower than the highest permitted dose. Maximum dosages of ≥3 antihypertensives were prescribed in 8.1% of patients with BP ≥140/90 mmHg. Mean daily urinary sodium excretion was 156 mmol (SD 70.4).

Conclusion Treatment efficacy of hypertension in Dutch kidney transplant recipients is low. Our data suggest that pharmacological treatment and advices on dietary salt restrictions can be intensified.