Adrian G. Stanley

High rates of non-adherence to antihypertensive treatment revealed by high-performance liquid chromatography-tandem mass spectrometry (HP LC-MS/MS) urine analysis

Objectives Non-adherence to therapy is an important cause of suboptimal blood pressure control but few practical tools exist to accurately and routinely detect it. We used a simple urine-based assay to evaluate the prevalence of antihypertensive treatment non-adherence and its impact on blood pressure in a specialist hypertension centre. Methods 208 hypertensive patients (125 new referrals, 66 follow-up patients with inadequate blood pressure control and 17 renal denervation referrals) underwent assessment of antihypertensive drug intake using high-performance liquid chromatography-tandem mass spectrometry (HP LC-MS/MS) urine analysis at the time of clinical appointment. A total of 40 most commonly prescribed antihypertensive medications (or their metabolites) were screened for in spot urine samples. Results Overall, 25% of patients were totally or partially non-adherent to antihypertensive treatment (total non-adherence 10.1%, partial non-adherence 14.9%). The highest prevalence of partial and total non-adherence was among follow-up patients with inadequate blood pressure control (28.8%) and those referred for consideration of renal denervation (23.5%), respectively. There was a linear relationship between blood pressure and the numerical difference in detected/prescribed antihypertensive medications—every unit increase in this difference was associated with 3.0 (1.1) mm Hg, 3.1 (0.7) mm Hg and 1.9 (0.7) mm Hg increase in adjusted clinic systolic blood pressure, clinic diastolic blood pressure (DBP) and 24 h mean daytime DBP (p=0.0051, p=8.62×10−6, p=0.0057), respectively. Conclusions Non-adherence to blood pressure lowering therapy is common, particularly in patients with suboptimal blood pressure control and those referred for renal denervation. HP LC-MS/MS urine analysis could be used to exclude non-adherence and better stratify further investigations and intervention.

Increased pulse wave velocity is not associated with elevated augmentation index in patients with diabetes

Objective Increased arterial stiffness is a risk factor for cardiovascular disease and is a feature associated with diabetes. Pulse wave velocity (PWV) is an accepted index of arterial stiffness and augmentation index (Al) derived from radial applanation tonometry has been advocated as a measurement of arterial stiffness. This study compares the relationship between PWV and Al in people with and without diabetes. Design and methods A total of 66 people with diabetes and 66 age-matched non-diabetic controls were studied. Central aortic pressure waves were generated using applanation tonometry over the radial artery and used to calculate Al. Carotid-femoral PWV (PWV cf ) was measured simultaneously. Results Relative to controls, diabetes was associated with increased pulse pressure (PP) and PWV cf (P<0.01). In contrast, Al did not differ between groups even after adjustment for heart rate. This observation remained consistent irrespective of diabetes type, arterial site, and the presence or absence of antihypertensive therapy. Multiple regression analysis revealed diabetes to be a significant determinant of PWV cf , but not Al. Conclusions PP and PWV cf are increased in people with diabetes, but this is not associated with increased Al. These findings conclusively demonstrate that Al is not a reliable measure of arterial stiffness in people with diabetes.

Mechanical strain-induced human vascular matrix synthesis: The role of angiotensin II

Introduction: Reduced vascular compliance in patients with hypertension results from an increase in extra-cellular matrix (ECM) protein deposition in blood vessels. At least two key factors, namely mechanical strain and neurohumoral mediators, for example Angiotensin II (Ang II), promote fibrogenesis within vessel walls; however potential interactions between these have not been clearly defined. This work examined the direct effect of mechanical strain on matrix mRNA expression and protein synthesis by human vascular smooth muscle (VSM) cells and identified the importance of renin-angiotensin system (RAS) activation in stretch-induced matrix production. Methods: Human VSM cells were exposed either to a cyclical mechanical strain regimen or to Ang II in the presence or absence of the Ang II receptor (AT1 R) antagonist losartan or its more potent metabolite EXP3174. Analysis of matrix mRNA expression (Northerns) and protein synthesis (ELISA) and cellular AT1-receptor protein expression (Westerns) were determined. Results: Ang II increased both collagen α1 (92%, SEM +/-20%) mRNA expression and fibronectin (21% +/- 6%) protein synthesis in static VSM cells compared with unstimulated controls.The effect of Ang II was attenuated by antagonism of the AT 1-receptor (AT1 R). Similarly, mechanical strain induced an increase in both collagen α1 (102% +/- 30%) mRNA expression and fibronectin (50% +/-21%) protein synthesis. Surprisingly, in the absence of exogenous Ang II, AT1-receptor blockade attenuated this stretch-induced increase in matrix synthesis. Mechanical strain also induced an increase in total cellular AT1-receptor protein (30.7% +/- 3.5%) compared with static cells. Conclusion: Both mechanical strain and Ang II increased matrix gene expression and protein synthesis by human VSM cells. The effect of strain was attenuated by AT 1-receptor antagonism. Our results further suggest that mechanical strain may sensitise human VSM cells to the fibrogenic actions of Ang II, perhaps via upregulation of the AT1-receptor.

Changes in transcription profile and cytoskeleton morphology in pelvic ligament fibroblasts in response to stretch: the effects of estradiol and levormeloxifene

Failure of ligamentous support of the genital tract to resist intra-abdominal pressure is a plausible underlying mechanism for the development of pelvic organ prolapse, but the nature of the molecular response of pelvic tissue support remains unknown. We hypothesized that the expression of genes coding for proteins involved in maintaining the cellular and extracellular integrity would be altered as a result of mechanical stretch. Therefore, cDNA microarrays were used to examine the difference in transcriptional profile in RNA of primary culture fibroblasts subjected to mechanical stretch and those that remained static. Out of 34 mechano-responsive genes identified (P < 0.05), four were coding for regulation of actin cytoskeleton remodelling, and its interaction with the extracellular matrix proteins; these are phosphatidyl inositol-4-phosphate 5-kinase (PIP5K1C), the human signal-induced proliferation associated gene-1 (SIPA-1), TNFRSF1A-associated via death domain (TRADD) and deoxyribonuclease 1-like 1 (DNase 1-L1). The transcriptosomal changes led us to investigate the phenotypic consequences of stretch, levormeloxifene and estradiol (E(2)) on the cytoskeleton of cultured fibroblasts. The percentage of cells with abnormal F-actin configuration was significantly higher in fibroblasts subjected to stretch compared with the static model (P < 0.0001). Levormeloxifene caused similar significant alterations in actin morphology of the static fibroblasts. The use of E(2) did not reverse the process or protect the cells from the effect of stretch, but significantly increased the rate of fibroblast proliferation, suggestive of a role in healing process. Mechanical stretch and/or levormeloxifene disturb the fibroblasts ability to maintain the cytoskeleton architecture and we speculate that they may disrupt ligamentous integrity and result in clinical prolapse.

Rapid telomere attrition in cardiac tissue of the ageing Wistar rat

Many studies show an association between ageing and mean telomere length in DNA isolated from peripheral blood mononuclear cells, few studies have examined less accessible tissues. This study has two objectives: (i) to define the best method to prepare rodent DNA for telomere length measurement by Southern blotting and (ii) to determine whether there are differential rates of telomere attrition in different rodent tissues. We found that the use of agarose plugs for DNA isolation was essential for the accurate measurement of rodent telomere length. Tissue was collected from neonatal (3 days) or aged (18-24 months) male Wistar rats and terminal restriction fragment (TRF) length was measured by Southern blotting. Cardiac tissue from aged rats showed a 38% loss of TRF length compared with newborn animals (p<0.001, n=13), this contrasts with much smaller reductions in brain (1.6%), liver (14.2%), kidney (8.9%) and lung (9.7%). This study demonstrates that the methods of DNA preparation are critical for accurate measurement of telomeres in rodent tissues. Moreover, we show differential rates of telomere attrition in rat tissues, the heart being most susceptible to telomere loss. These observations could have important implications for the study of age-specific changes in tissue function.

Screening for non-adherence to antihypertensive treatment as a part of the diagnostic pathway to renal denervation

Renal denervation is a potential therapeutic option for resistant hypertension. A thorough clinical assessment to exclude reversible/spurious causes of resistance to antihypertensive therapy is required prior to this procedure. The extent to which non-adherence to antihypertensive treatment contributes to apparent resistance to antihypertensive therapy in patients considered for renal denervation is not known. Patients (n=34) referred for renal denervation entered the evaluation pathway that included screening for adherence to antihypertensive treatment by high-performance liquid chromatography-tandem mass spectrometry-based urine analysis. Biochemical non-adherence to antihypertensive treatment was the most common cause of non-eligibility for renal denervation—23.5% of patients were either partially or completely non-adherent to prescribed antihypertensive treatment. About 5.9% of those referred for renal denervation had admitted non-adherence prior to performing the screening test. Suboptimal pharmacological treatment of hypertension and ‘white-coat effect’ accounted for apparently resistant hypertension in a further 17.7 and 5.9% of patients, respectively. Taken together, these three causes of pseudo-resistant hypertension accounted for 52.9% of patients referred for renal denervation. Only 14.7% of referred patients were ultimately deemed eligible for renal denervation. Without biochemical screening for therapeutic non-adherence, the eligibility rate for renal denervation would have been 38.2%. Non-adherence to antihypertensive treatment and other forms of therapeutic pseudo-resistance are by far the most common reason of ‘resistant hypertension’ in patients referred for renal denervation. We suggest that inclusion of biochemical screening for non-adherence to antihypertensive treatment may be helpful in evaluation of patients with ‘resistant hypertension’ prior to consideration of renal denervation.

Biochemical Screening for Nonadherence Is Associated With Blood Pressure Reduction and Improvement in Adherence

We hypothesized that screening for nonadherence to antihypertensive treatment using liquid chromatography-tandem mass spectrometry–based biochemical analysis of urine/serum has therapeutic applications in nonadherent hypertensive patients. A retrospective analysis of hypertensive patients attending specialist tertiary care centers was conducted in 2 European countries (United Kingdom and Czech Republic). Nonadherence to antihypertensive treatment was diagnosed using biochemical analysis of urine (United Kingdom) or serum (Czech Republic). These results were subsequently discussed with each patient, and data on follow-up clinic blood pressure (BP) measurements were collected from clinical files. Of 238 UK patients who underwent biochemical urine analysis, 73 were nonadherent to antihypertensive treatment. Their initial urinary adherence ratio (the ratio of detected to prescribed antihypertensive medications) increased from 0.33 (0–0.67) to 1 (0.67–1) between the first and the last clinic appointments. The observed increase in the urinary adherence ratio in initially nonadherent UK patients was associated with the improved BP control; by the last clinic appointment, systolic and diastolic BPs were ≈19.5 and 7.5 mm Hg lower than at baseline (P=0.001 and 0.009, respectively). These findings were further corroborated in 93 nonadherent hypertensive patients from Czech Republic—their average systolic and diastolic BPs dropped by ≈32.6 and 17.4 mm Hg, respectively (P<0.001), on appointments after the biochemical analysis. Our data show that nonadherent hypertensive patients respond to liquid chromatography–tandem mass spectrometry-based biochemical analysis with improved adherence and significant BP drop. Such repeated biochemical analyses should be considered as a therapeutic approach in nonadherent hypertensive patients.

Dermatology and junior doctors: an evaluation of education, perceptions and self-assessed competencies.

Author Posting.

Disorganized junior doctors fail the MRCP (UK)

Career progression during undergraduate and early postgraduate years is currently determined by successfully passing examinations. Both academic factors (secondary school examination results, learning style and training opportunities) and non-academic factors (maturity, ethnic origin, gender and motivation) have been identified as predicting examination outcome. Few studies have examined organization skills. Disorganized medical students are more likely to perform poorly in end-of-year examinations but this observation has not been examined in junior doctors. This study asked whether organization skills relate to examination outcome amongst junior doctors taking the clinical Part II examination for the Membership of the Royal College of Physicians (Practical Assessment of Clinical Examination Skills). The study was conducted prospectively at four consecutive clinical courses that provided clinical teaching and practice to prepare trainees for the examination. Arrival time at registration for the course was the chosen surrogate for organization skills. Trainees were advised that they should arrive promptly at 8.00 a.m. for registration and it was explained that the course would start at 8.30 a.m. Recorded arrival times were compared with the pass lists published by the Royal College of Physicians. The mean arrival time was 8.17 a.m. A total of 81 doctors (53.3%) passed the examination with a mean arrival time of 8.14 a.m. However, 71 doctors failed the exam and arrived, on average, six minutes later than doctors who passed (p = 0.006). Better-prepared junior doctors were more likely to pass the final examination. Arriving on time represents a composite of several skills involved in the planning of appropriate travel arrangements and is therefore a valid marker of organization skills and preparation. This novel study has shown that good time-keeping skills are positively associated with examination outcome.

Is warfarin a contraindication to thrombolysis in acute ST elevation myocardial infarction

The use of thrombolysis to treat ST elevation myocardial infraction (MI) is well supported. Serious adverse events occur in 1–2% of patients.1 Warfarin is increasingly prescribed to patients at high cardiovascular risk and it is inevitable that these patients will present with an MI that warrants thrombolytic treatment. The British National Formulary and the American Heart Association both advise that patients on warfarin present a relative contraindication to thrombolysis, but this has resulted in uncertainty in providing patients with the optimum medical management. Streptokinase and tissue plasminogen activators activate the conversion of plasminogen to plasmin, which rapidly degrades formed thrombus. In contrast, warfarin inhibits the carboxylation of the vitamin K dependent clotting factors II, VII, IX and X (extrinsic system) rending these factors inactive. Anecdotally physicians differ in their advice regarding thrombolysis for patients prescribed warfarin. Before the present study, all acute care physicians and cardiologists at the University Hospitals of Leicester NHS Trust were surveyed anonymously about their use of thrombolysis for such patients. Three respondents (of 38 replies received) advised thrombolysis regardless of the international normalised ratio (INR). Of the others, 24 would advise thrombolysis only if the INR was less than 3. This was irrespective of grade and specialty. Primarily, the objective of this study was to investigate the thrombolysis complication rate among patients prescribed warfarin at the time of admission for an MI. For this purpose, we retrospectively …