Unaltered neurocardiovascular reactions to mental stress after renal sympathetic denervation.

Background: The impact of renal denervation (RDN) on muscle sympathetic nerve activity (MSNA) at rest remains controversial. Mental stress (MS) induces transient changes in sympathetic nerve activity, heart rate (HR) and blood pressure (BP). It is not known whether RDN modifies these changes.Purpose: The main objective was to assess the effect of RDN on MSNA and BP alterations during MS.Methods: In 14 patients (11 included in analysis) with resistant hypertension multi-unit MSNA, BP (Finometer ®) and HR were assessed at rest and during forced arithmetics at baseline and 6 months after RDN.Results: Systolic office BP decreased significantly 6 months after RDN (185 ± 29 vs.175 ± 33 mmHG; p = 0.04). No significant changes in MSNA at rest (68 ± 5 vs 73 ± 5 bursts/100hb; p = 0.43) were noted and no significant stress-induced change in group averaged sympathetic activity was found pre- (101 ± 24%; p = 0.9) or post-intervention (108 ± 26%; p = 0.37). Stress was associated with significant increases in mean arterial BP (p < 0.01) and HR (p < 0.01) at baseline, reactions which remained unaltered after intervention. We did not note any correlation between sympathetic nerve activity and BP changes after RDN.Conclusion: Thus, in our group of resistant hypertensives we find no support for the hypothesis that the BP-lowering effect of RDN depends on altered neurovascular responses to stress.

Impact of age and comorbidity on risk stratification in idiopathic pulmonary arterial hypertension.

Recent reports from worldwide pulmonary hypertension registries show a new demographic picture for patients with idiopathic pulmonary arterial hypertension (IPAH), with an increasing prevalence among the elderly.We aimed to investigate the effects of age and comorbidity on risk stratification and outcome of patients with incident IPAH.The study population (n=264) was categorised into four age groups: 18-45, 46-64, 65-74 and ≥75 years. Individual risk profiles were determined according to a risk assessment instrument, based on the European Society of Cardiology and the European Respiratory Society guidelines. The change in risk group from baseline to follow-up (median 5 months) and survival were compared across age groups. In the two youngest age groups, a significant number of patients improved (18-45 years, Z= -4.613, p<0.001; 46-64 years, Z= -2.125, p=0.034), but no significant improvement was found in the older patient groups. 5-year survival was highest in patients aged 18-45 years (88%), while the survival rates were 63%, 56% and 36% for patients in the groups 46-64, 65-74 and ≥75 years, respectively (p<0.001). Ischaemic heart disease and kidney dysfunction independently predicted survival.These findings highlight the importance of age and specific comorbidities as prognostic markers of outcome in addition to established risk assessment algorithms.