Frequency of laboratory testing and associated abnormalities in patients with hypertension

Clinical practice guidelines recommend several routine laboratory tests in patients diagnosed with hypertension. However, the rates of clinically relevant laboratory abnormalities are unknown. Therefore, we conducted a retrospective cohort study using administrative and laboratory data of patients diagnosed with hypertension between April 2010 and March 2015 in Alberta, Canada. Laboratory investigations for renal function, serum electrolytes (sodium and potassium), low‐density lipoprotein (LDL) cholesterol, and diabetes (fasting blood glucose and hemoglobin A1c), measured within 1 year of diagnosis, were examined, and the frequency of abnormalities determined. A total of 225 296 cases of incident hypertension were identified. Of these, 74.3% received at least one of the four guideline‐recommended laboratory tests, but only 42.3% received all four tests. Patients who received any testing, compared to subjects who did not, were on average older (median age 55.9 vs 51.2 years, P < .001) and had more comorbidity (14.5% vs 2.8% with a Charlson comorbidity index ≥ 3, P < .001). Laboratory abnormalities with the potential to affect clinical decision‐making were more common among multi‐comorbid patients. Patients with renal dysfunction (6.7% vs 11.6%, 26.3%, P < .001), electrolyte abnormalities (9.8% vs 12.6%, 20.5%, P < .001), and diabetes (13.4% vs 25.1% vs 38.8%, P < .001) were found in patients with Charlson scores of 0 vs 1‐2 vs ≥3, respectively. Our study found most patients diagnosed with hypertension received some laboratory testing, but rates of laboratory testing and frequency of abnormalities varied by clinical context. Testing and abnormalities detected were both more common among older patients and patients with comorbidities.     

Precursors of cardiorespiratory events in infants detected by home memory monitor

In 1,079 infants monitored for >700,000 hr at home for apnea or bradycardia, we found an association between infants having multiple events exceeding conventional or a priori defined more extreme thresholds and less favorable developmental outcome at 1 year of age than infants with few or no events. If it is necessary to prevent such events to minimize risk for developmental morbidity, there is reason to determine whether there are disturbances in advance of the apnea or bradycardia that herald their onset. In the 85 infants with at least 1 extreme event and 1 conventional event, we hypothesized that apnea and bradycardia do not occur de novo but rather are preceded by cardiorespiratory and hemoglobin O2 saturation changes. We compared recorded time intervals preceding these events, and we analyzed three preceding time intervals for each conventional and extreme event, and each non-event recording: Time-2 hr: up to 2 hr before; Time-1 hr: up to 1 hr before; and Time-75 sec: the 75 sec immediately preceding each event. O2 saturation progressively decreased preceding both conventional and extreme events, and progressive increases occurred in heart and breathing rate variability. Duration of respiratory pauses and of periodic breathing progressively increased preceding conventional events, respiratory rate variability increased immediately preceding conventional events and at 1 hr preceding extreme events, and O2 saturation decreased immediately preceding both conventional and extreme events. Thus, conventional and extreme events do not occur de novo but rather are preceded by autonomic instability of the cardiorespiratory system.     

Microabluminuria in arterial hypertension. Measurement, variables, interpretation, recommendations

Permanent hypertension is frequently associated with increased glomerular permeability to albumin at an early stage, indicating renal involvement and endothelial dysfunction. The definition of microalbuminuria is an urinary albumin excretion of 30-300 mg/24 hrs, confirmed on two occasions over a 3 month period. It may also be expressed in microgram/min, m/l or mg/mmol of creatinine. Radio-immunological, immunonephelometric methods and Elisa are specific and the most sensitive methods of measurement. There is a large intra-individual variability (25-60%) making it essential to repeat measurements always by the same technique. The prevalence of microalbuminuria is 5-8% in the general population and 6-24% in hypertensive patients. When present, it is a marker of increased cardiovascular risk. Clinical recommendations suggest adaptation of urinary collection according to the context: screening, diagnosis or clinical research. It is always necessary to start by dip-stick detection of proteinuria, haematuria or urinary infection. Clinical research requires repeated measurement of 24 hour microalbuminuria, sometimes divided into two periods of day and night, often associated with ambulatory blood pressure recordings and renal function tests. Studies of the effects of anti-hypertensive drugs on microalbuminuria could provide better evaluation. In conclusion, measurement of microalbuminuria remains a tool of clinical research allowing an assessment of cardiovascular and renal risk of hypertensive patients.     

Association of frontal QRS-T angle--age risk score on admission electrocardiogram with mortality in patients admitted with an acute coronary syndrome

Risk assessment is central to the management of acute coronary syndromes. Often, however, assessment is not complete until the troponin concentration is available. Using 2 multicenter prospective observational studies (Evaluation of Methods and Management of Acute Coronary Events [EMMACE] 2, test cohort, 1,843 patients; and EMMACE-1, validation cohort, 550 patients) of unselected patients with acute coronary syndromes, a point-of-admission risk stratification tool using frontal QRS-T angle derived from automated measurements and age for the prediction of 30-day and 2-year mortality was evaluated. Two-year mortality was lowest in patients with frontal QRS-T angles <38° and highest in patients with frontal QRS-T angles >104° (44.7% vs 14.8%, p <0.001). Increasing frontal QRS-T angle-age risk (FAAR) scores were associated with increasing 30-day and 2-year mortality (for 2-year mortality, score 0 = 3.7%, score 4 = 57%; p <0.001). The FAAR score was a good discriminator of mortality (C statistics 0.74 [95% confidence interval 0.71 to 0.78] at 30 days and 0.77 [95% confidence interval 0.75 to 0.79] at 2 years), maintained its performance in the EMMACE-1 cohort at 30 days (C statistics 0.76 (95% confidence interval 0.71 to 0.8] at 30 days and 0.79 (95% confidence interval 0.75 to 0.83] at 2 years), in men and women, in ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction, and compared favorably with the Global Registry of Acute Coronary Events (GRACE) score. The integrated discrimination improvement (age to FAAR score at 30 days and at 2 years in EMMACE-1 and EMMACE-2) was p <0.001. In conclusion, the FAAR score is a point-of-admission risk tool that predicts 30-day and 2-year mortality from 2 variables across a spectrum of patients with acute coronary syndromes. It does not require the results of biomarker assays or rely on the subjective interpretation of electrocardiograms.     

Serum 25-hydroxyvitamin d concentration and mortality from heart failure and cardiovascular disease, and premature mortality from all-cause in United States adults

We aimed to examine associations between serum 25-hydroxyvitamin D (25[OH]D) concentration and mortality from heart failure (HF) and cardiovascular disease (CVD) and premature death from all causes using data from the Third National Health and Nutrition Examination Survey, which included 13,131 participants (6,130 men, 7,001 women) ≥35 years old at baseline (1988 to 1994) and followed through December 2000. Premature death was defined all-cause death at <75 years of age. Results indicated that during an average 8-year follow-up, there were 3,266 deaths (24.9%) including 101 deaths from HF, 1,451 from CVD, and 1,066 premature all-cause deaths. Among HF deaths, 37% of decedents had serum 25(OH)D levels <20 ng/ml, whereas only 26% of those with non-HF deaths had such levels (p <0.001). Multivariate-adjusted Cox model indicated that subjects with serum 25(OH)D levels <20 ng/ml had 2.06 times higher risk (95% confidence interval 1.01 to 4.25) of HF death than those with serum 25(OH)D levels ≥30 ng/ml (p <0.001). In addition, hazard ratios (95% confidence intervals) for premature death from all causes were 1.40 (1.17 to 1.68) in subjects with serum 25(OH)D levels <20 ng/ml and 1.11 (0.93 to 1.33) in those with serum 25(OH)D levels of 20 to 29 ng/ml compared to those with serum 25(OH)D levels ≥30 ng/ml (p <0.001, test for trend). In conclusion, adults with inadequate serum 25(OH)D levels have significantly higher risk of death from HF and all CVDs and all-cause premature death.     

Antialbuminuric advantage of cilnidipine compared with L-type calcium channel blockers in type 2 diabetic patients with normoalbuminuria and microalbuminuria

We evaluated the antialbuminuric advantage of cilnidipine, an N/L-type calcium channel blocker (CCB), compared with L-type CCBs in diabetic patients with normoalbuminuria and microalbuminuria. The study was a multicenter, non-randomized crossover trial. Participants were 90 type 2 diabetic patients exhibiting either normo- or microalbuminuria, and undergoing CCB treatment for ≥6 months prior to study entry. The CCB at the time of entry was continued for the first 6 months (Period 1). Treatment was subsequently switched from cilnidipine to an L-type CCB, or vice versa, for the second 6-month observation period (Period 2). During Period 1, the L-type CCB group showed a significant increase of urinary albumin excretion (UAE) over time, while the cilnidipine group showed no significant elevation. During Period 2, switching of the treatment from the L-type CCB to cilnidipine resulted in significant reduction of the UAE, whereas switching from cilnidipine to the L-type CCB resulted in no significant change in the UAE. This study demonstrated that the antialbuminuric effect of Cilnidipine, but not the L-type CCBs, was sustained even in patients treated for a long time. In addition, the antialbuminuric effect can be anticipated after switching from an L-type CCB to cilnidipine, but not vice versa.