Blood pressure altering method affects correlation with pulse arrival time.

OBJECTIVE: Pulse arrival time (PAT) is a potential main feature in cuff-less blood pressure (BP) monitoring. However, the precise relationship between BP parameters and PAT under varying conditions lacks a complete understanding. We hypothesize that simple test protocols fail to demonstrate the complex relationship between PAT and both SBP and DBP. Therefore, this study aimed to investigate the correlation between PAT and BP during two exercise modalities with differing BP responses using an unobtrusive wearable device. METHODS: Seventy-five subjects, of which 43.7% had a prior diagnosis of hypertension, participated in an isometric and dynamic exercise test also including seated periods of rest prior to, in between and after. PAT was measured using a prototype wearable chest belt with a one-channel electrocardiogram and a photo-plethysmography sensor. Reference BP was measured auscultatory. RESULTS: Mean individual correlation between PAT and SBP was -0.82 ± 0.14 in the full protocol, -0.79 ± 0.27 during isometric exercise and -0.77 ± 0.19 during dynamic exercise. Corresponding correlation between PAT and DBP was 0.25 ± 0.35, -0.74 ± 0.23 and 0.39 ± 0.41. CONCLUSION: The results confirm PAT as a potential main feature to track changes in SBP. The relationship between DBP and PAT varied between exercise modalities, with the sign of the correlation changing from negative to positive between type of exercise modality. Thus, we hypothesize that simple test protocols fail to demonstrate the complex relationship between PAT and BP with emphasis on DBP.

Content and system development of a digital patient-provider communication tool to support shared decision making in chronic health care: InvolveMe.

BACKGROUND: Chronic conditions present major health problems, affecting an increasing number of individuals who experience a variety of symptoms that impact their health related quality of life. Digital tools can be of support in chronic conditions, potentially improving patient-provider communication, promoting shared decision making for treatment and care, and possibly even improving patient outcomes. This study aimed to develop a digital tool for patient-provider communication in chronic health care settings and describes the data collection and subsequent content and software development of the InvolveMe tool. InvolveMe will provide patients with the opportunity to report symptoms and preferences to their health care providers (HCP), and to use secure messaging to interact with the HCPs. METHOD: The study employed a combination of interviews with patients with chronic conditions and focus groups with HCPs, examining experiences with chronic conditions and the potential use of a digital tool for support. Participants were recruited from two outpatient clinics at a university hospital. Data collected from interviews and focus groups were analysed using thematic analysis. Content and software development was informed by the data collection and by tool development workshops. RESULTS: Analyses from interviews with patients (n = 14) and focus groups with HCPs (n = 11) generated three main themes: 1) Making symptoms and challenges visible, 2) Mastering a new life, and 3) Digital opportunities for follow-up. Each main theme generated separate subthemes. Theme 1 and 2 gave input for content development of the symptom and needs assessment part of the tool, while theme 3 provided ideas for the software development of the InvolveMe tool. Tool development workshops with patients (n = 6) and HCPs (n = 6) supplemented the development. CONCLUSIONS: A digital tool such as InvolveMe has the potential to support shared decision making for patients with chronic health conditions. Through integration with an existing patient portal such a tool can provide opportunities for meaningful interactions and communication between patients and HCP's, particularly with regards to symptoms, needs and preferences for care.

Renal sympathetic denervation in patients with treatment-resistant hypertension after witnessed intake of medication before qualifying ambulatory blood pressure.

It is unknown whether the decline in blood pressure (BP) after renal denervation (RDN) is caused by denervation itself or concomitantly improved drug adherence. We aimed to investigate the BP lowering effect of RDN in true treatment-resistant hypertension by excluding patients with poor drug adherence. Patients with resistant hypertension (n=18) were referred for a thorough clinical and laboratory work-up. Treatment-resistant hypertension was defined as office systolic BP>140 mm Hg, despite maximally tolerated doses of ≥ 3 antihypertensive drugs, including a diuretic. In addition, ambulatory daytime systolic BP>135 mm Hg was required after witnessed intake of antihypertensive drugs to qualify. RDN (n=6) was performed with Symplicity Catheter System. The mean office and ambulatory BPs remained unchanged at 1, 3, and 6 months in the 6 patients, whereas there was no known change in antihypertensive medication. Two patients, however, had a fall in both office and ambulatory BPs. Our findings question whether BP falls in response to RDN in patients with true treatment-resistant hypertension. Additional research must aim to verify potential BP lowering effect and identify a priori responders to RDN before this invasive method can routinely be applied to patients with drug-resistant hypertension. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01673516.

From treatment to organ damage; a 5-year follow-up study of ambulatory blood pressure in essential hypertension. Diversity between development of left ventricular hypertrophy and urinary albumin excretion.

This study aimed to assess blood pressure (BP) profile, BP control, left ventricular hypertrophy (LVH) and albumin/creatinine ratio (ACR) in urine after 5 years of antihypertensive treatment in subjects with newly diagnosed essential hypertension. Fifty-four subjects were included and prescribed calcium-channel blocker in monotherapy during an 8-week period, and later 46 subjects (34 men, 12 women, 53.1+/-8.6 years) attended a 5-year follow-up visit at the hypertension clinic. They underwent 24-h ambulatory BP monitoring (ABPM), ECG and ACR at baseline and after 5 years. Echocardiography performed after 5 years revealed LVH in 54% of the subjects, while there was no change in Cornell product, an ECG criterion for LVH. BP control assessed by office BP was 33%, and only 20% using 24-h ABP. Night-time fall in BP was significantly attenuated from 13.2+/-5.9% to 10.7+/-6.0%, p = 0.01 for systolic BP and from 13.3+/-6.9% to 9.8+/-6.8%, p = 0.004 for diastolic BP. The number of dippers decreased after 5 years, but this did not reach statistical significance. In contrast to the lack of change in Cornell product, there was a significant decrease in ACR, and 93% of the subjects had ACR<1.5 mg/mmol after 5 years compared with 57% at baseline (p<0.001). Thus, ABPM should be encouraged in the follow-up of all hypertensive subjects as it reveals better inadequate BP control than office BP and gives information about night-time fall, as this may explain the high prevalence of LVH. The diversity in development of LVH and ACR during antihypertensive treatment needs to be verified.

Slow recovery from severe inorganic arsenic poisoning despite treatment with DMSA (2.3-dimercaptosuccinic acid).

A 39-year-old woman was hospitalized for nausea, diarrhea, vomiting, and weakness of unknown etiology. Her condition progressively deteriorated and she developed multiple organ failure and tetraplegia. The diagnosis of inorganic arsenic poisoning was established by measurements of arsenic in urine and serum, showing 2,000 microg/L (normal < 10 microg/L) and 290 mug/Kg (normal < 2 microg/Kg), respectively. Hair arsenic was 57 mg/kg (normal < 0.2 mg/kg). Chelating therapy with 2.3-dimercaptosuccinic acid (DMSA) 600 mg three times daily was given for a period of 45 days with three abruption periods during a total of 13 days. The clinical manifestations of arsenic toxicosis disappeared very slowly and five years after the hospitalization she still suffers from peripheral neuropathy. Although the use of DMSA was associated with increased urinary elimination of arsenic and a decrease in blood arsenic concentrations, DMSA treatment probably had no significant effect on the total body clearance in our patient. The source of the poisoning was never detected, nor the motivation behind it. Criminal intent was suspected, but no verdict was given.

Office blood pressure measurements overestimate blood pressure control in renal transplant patients.

OBJECTIVE: As hypertension is an important risk factor for renal allograft failure, we aimed to assess blood pressure control in renal transplant patients with deteriorating graft function using different methods of blood pressure measurements. METHODS: Forty-nine patients with a graft survival of >1 year, and with more than a two-fold increase in urinary albumin excretion, and/or an increase in serum creatinine level >20% during the previous 12 months, were included. Office blood pressure and home BP were measured, and ambulatory blood pressures were obtained in all patients. RESULTS: The mean office blood pressure (133.2+/-16.3/81.7+/-9.6 mmHg) and 24 h ambulatory blood pressure (133.1+/-12.0/79.8+/-8.3 mmHg) were similar. Home blood pressure in the morning (144.2+/-23.3/87.1+/-12.7 mmHg) and evening (143.2+/-20.6/86.4+/-10.3 mmHg) were significantly higher than ambulatory blood pressure (P<0.001 for both). Only 18% of the patients exhibited a reduction of >or=10% in systolic blood pressure during nighttime while 39% had an overt rise. Adequate blood pressure control was found in 53% of the patients using office blood pressure (<140/90 mmHg), contrasting 29% using home blood pressure (<135/85 mmHg), and 16% using mean 24-h ambulatory blood pressure (<125/80 mmHg). These findings were substantiated by the use of receiver-operating characteristic curve analysis. CONCLUSIONS: Using the 24-h blood pressure as a standard, home blood pressure was superior to office blood pressure in estimating blood pressure control in renal transplant patients. Nocturnal hypertension, however, was observed frequently, adding important clinical information about blood pressure control in this high-risk population.

Clinical utility and applicability of smoothness index, normalized smoothness index and individualized RDH index during treatment of essential hypertension.

The purpose of this study was to assess the clinical utility of the smoothness index (SI) and normalized SI (SIn), measures of duration and homogeneity of blood pressure (BP) reduction, during an observation period without antihypertensive therapy followed by a treatment period using dihydropyridines (DHP) in 54 newly diagnosed and previously untreated subjects (age 46.9 +/- 9.1 years) with essential hypertension. In addition, we aimed to describe the reduction-duration-homogeneity (RDH) index for statistical assessment of the BP reduction in the individual patient. Twenty-four-hour BP was lowered during treatment (139.2 +/- 13.9/ 91.0 +/- 7.6 mmHg vs 130.9 +/- 11.3/85.2 +/- 5.2 mmHg, p < 0.001/p = 0.001). SI showed great interindividual variation, and increased from zero to 0.9 +/- 0.8 (systolic BP) and 0.8 +/- 0.7 (diastolic BP) after treatment (p < 0.001 for both), similar results were obtained for SI(n). The RDH index revealed BP reduction in agreement with the change in individual 24-h, daytime and night-time BP. Although SI and SI(n) may add important information regarding the homogeneity of the antihypertensive effect in a group of patients, and the RDH index for the individual patient, conclusions regarding antihypertensive efficacy can be obtained from assessment of the 24-h, daytime and night-time BP changes and ambulatory BP profiles. Based on our findings, we do not recommend the use of SI or RDH index in the clinical practice.

Reproducibility of blood pressure variability, white-coat effect and dipping pattern in untreated, uncomplicated and newly diagnosed essential hypertension.

OBJECTIVE: To investigate the reproducibility of blood pressure (BP) variability, white-coat effect (WCE) and nocturnal dipping pattern in untreated patients with uncomplicated essential hypertension using 24-hour ambulatory BP monitoring (ABPM). METHODS: Seventy-five newly diagnosed, untreated essential hypertensive subjects (54 men, 21 women 47.6 +/- 9.3 years) were recruited for the study based on conventional measured BP from a total of 180 patients referred for ABPM. Of these, 65 patients underwent repeated ABPM after 4 weeks observation without treatment. Reproducibility of BP, nocturnal dipping pattern, WCE and BP variability were assessed using different methods. RESULTS: The average 24-hour BP (140.8 +/- 11.9/91.8 +/- 6.4 vs. 140.5 +/- 14.5/90.7 +/- 7.6 mmHg, ns) or PP (49.6 +/- 10.8 vs. 49.8 +/- 9.8 mmHg, ns) did not change, nor did daytime BP or PP. The WCE diminished significantly during the observation period (reduction in SBP WCE delta8.2 +/- 12.5 mmHg, p < 0.0001, in DBP WCE, delta3.3 +/- 9.2 mmHg, p = 0.008 and in PP WCE delta4.8 +/- 11.2 mmHg, p = 0.002). Variability in SBP, DBP and PP decreased consistently and significantly during the observation period. The nocturnal dipping pattern was unchanged in 82% of the patients. In 12% non-dipping pattern was converted to dipping pattern after repeated measurement. CONCLUSION: Average ABPs are highly reproducible in patients with uncomplicated essential hypertension of limited duration. Similarly, nocturnal dipping pattern reproduced satisfactorily. These measures have important clinical applicability. The white-coat effect as well as variability are greatly attenuated during repeated measurements, and these measures may thus be of less utility in clinical practice.