The recanalization after thrombolysis as surrogate for clinical outcomes in patients with ST-segment elevation acute myocardial infarction: A systematic review and meta-regression analysis of data from randomized controlled trials.

AIMS: Thrombolytic therapy has been known to be effective in reducing clinical outcomes and increasing recanalization rate among patients with ST-segment elevation acute myocardial infarction (STEMI). However, whether post-thrombolysis recanalization could be used as a surrogate for clinical outcomes is unknown. METHODS: We systematically searched PubMed, EMBASE and the Cochrane Library database to identify randomized controlled trials (RCT) that examined effects of thrombolytic agents in STEMI. Recanalization was defined as TIMI grade 2 or 3 flow. The primary outcome was in-hospital all-cause mortality. Secondary outcomes included in-hospital and 30-day recurrent myocardial infarction (re-MI), composite of death and re-MI, major bleeding and all bleeding. Random-effects meta-regression was used for analysis. RESULTS: We identified 111 eligible study arms and 52 eligible comparisons from 58 RCTs involving 16 536 patients. Our analyses showed that among study arms recanalization rate was significantly inversely associated with the incidence of in-hospital all-cause mortality (ß: -0.07, 95% confidence interval [CI]: -0.13 to -0.02), re-MI (ß: -0.09, 95%CI: -0.18 to -0.01) and the composite of death and re-MI (ß: -0.17, 95%CI: -0.28 to -0.05), and positively associated with in-hospital all bleeding but not with major bleeding. Among paired comparisons, the difference in recanalization rate was associated with the corresponding difference in incidence of in-hospital all-cause mortality (ß: -0.15, 95%CI: -0.28 to -0.01) but the relationship was not significant for any other outcome. CONCLUSION: Pooled evidence from RCTs suggest the potential use of recanalization as a surrogate for clinical outcomes in evaluating the efficacy of thrombolysis among patients with STEMI.

Association of Perioperative Myocardial Injury with 30-Day and Long-Term Mortality in Older Adult Patients Undergoing Orthopedic Surgery in China.

BACKGROUND Myocardial injury after noncardiac surgery (MINS) is common and associated with postoperative mortality. We assessed MINS occurrence and association with 30-day and long-term mortality in older adult patients undergoing orthopedic surgery in China. MATERIAL AND METHODS This was a retrospective study of consecutive patients who underwent orthopedic surgery between January 1, 2009, and December 31, 2017, at Beijing Jishuitan Hospital. MINS was defined as postoperative troponin I peak elevation above the 99th percentile upper reference limit (>0.034 µg/L) within 30 days after surgery. Outcomes were 30-day postoperative mortality and long-term all-cause mortality. RESULTS From 34 901 patients, 5897 (16.9%) had serial troponin I measurements, and 266 (4.5%) had MINS after surgery. Mean patient age was 71.1±9.2 years; 32.9% were male. Among patients with MINS, 180 had myocardial infarction (MI) (3.2%). Patients with MI had higher 30-day and long-term mortality than those without MI (8.9% vs 1.2%; P<0.016 and 18.9% vs 3.5%; P=0.001). Male sex (OR 5.87, 95% CI 1.75-19.67; P=0.004), RCRI ≥2 (OR 5.05, 95% CI 1.67-15.31; P=0.004), and MI (OR 9.13, 95% CI 1.13-73.63; P=0.011) were independently associated with 30-day mortality. Age (HR 1.07, 95% CI 1.03-1.11; P=0.001), male sex (HR 2.96, 95% CI 1.51-5.80; P=0.002), RCRI ≥2 (HR 2.01, 95% CI 1.03-3.94; P=0.041), orthopedic trauma (HR 3.40, 95% CI 1.00-11.44; P=0.049), and MI (HR 7.33, 95% CI 2.22-24.20; P=0.001) were predictors of 2-year mortality. CONCLUSIONS Perioperative MI was independently associated with 30-day and long-term mortality after orthopedic surgery, providing a potential indicator of high risk of mortality in patients who could benefit from targeted prevention and intervention.

A Cluster-Randomized, Controlled Trial of a Simplified Multifaceted Management Program for Individuals at High Cardiovascular Risk (SimCard Trial) in Rural Tibet, China, and Haryana, India.

BACKGROUND: In rural areas in China and India, the cardiovascular disease burden is high but economic and healthcare resources are limited. This study (the Simplified Cardiovascular Management Study [SimCard]) aims to develop and evaluate a simplified cardiovascular management program delivered by community health workers with the aid of a smartphone-based electronic decision support system. METHODS AND RESULTS: The SimCard study was a yearlong cluster-randomized, controlled trial conducted in 47 villages (27 in China and 20 in India). Recruited for the study were 2086 individuals with high cardiovascular risk (aged ≥40 years with self-reported history of coronary heart disease, stroke, diabetes mellitus, and/or measured systolic blood pressure ≥160 mm Hg). Participants in the intervention villages were managed by community health workers through an Android-powered app on a monthly basis focusing on 2 medication use and 2 lifestyle modifications. In comparison with the control group, the intervention group had a 25.5% (P<0.001) higher net increase in the primary outcome of the proportion of patient-reported antihypertensive medication use pre- and post-intervention. There were also significant differences in certain secondary outcomes: aspirin use (net difference: 17.1%; P<0.001) and systolic blood pressure (-2.7 mm Hg; P=0.04). However, no significant changes were observed in the lifestyle factors. The intervention was culturally tailored, and country-specific results revealed important differences between the regions. CONCLUSIONS: The results indicate that the simplified cardiovascular management program improved quality of primary care and clinical outcomes in resource-poor settings in China and India. Larger trials in more places are needed to ascertain the potential impacts on mortality and morbidity outcomes. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01503814.

Tenecteplase versus alteplase in treatment of acute ST-segment elevation myocardial infarction: A randomized non-inferiority trial.

BACKGROUND: A phase II trial on recombinant human tenecteplase tissue-type plasminogen activator (rhTNK-tPA) has previously shown its preliminary efficacy in ST elevation myocardial infarction (STEMI) patients. This study was designed as a pivotal postmarketing trial to compare its efficacy and safety with rrecombinant human tissue-type plasminogen activator alteplase (rt-PA) in Chinese patients with STEMI. METHODS: In this multicenter, randomized, open-label, non-inferiority trial, patients with acute STEMI were randomly assigned (1:1) to receive an intravenous bolus of 16 mg rhTNK-tPA or an intravenous bolus of 8 mg rt-PA followed by an infusion of 42 mg in 90 min. The primary endpoint was recanalization defined by thrombolysis in myocardial infarction (TIMI) flow grade 2 or 3. The secondary endpoint was clinically justified recanalization. Other endpoints included 30-day major adverse cardiovascular and cerebrovascular events (MACCEs) and safety endpoints. RESULTS: From July 2016 to September 2019, 767 eligible patients were randomly assigned to receive rhTNK-tPA ( n = 384) or rt-PA ( n = 383). Among them, 369 patients had coronary angiography data on TIMI flow, and 711 patients had data on clinically justified recanalization. Both used a -15% difference as the non-inferiority efficacy margin. In comparison to rt-PA, both the proportion of patients with TIMI grade 2 or 3 flow (78.3% [148/189] vs. 81.7% [147/180]; differences: -3.4%; 95% confidence interval [CI]: -11.5%, 4.8%) and clinically justified recanalization (85.4% [305/357] vs. 85.9% [304/354]; difference: -0.5%; 95% CI: -5.6%, 4.7%) in the rhTNK-tPA group were non-inferior. The occurrence of 30-day MACCEs (10.2% [39/384] vs. 11.0% [42/383]; hazard ratio: 0.96; 95% CI: 0.61, 1.50) did not differ significantly between groups. No safety outcomes significantly differed between groups. CONCLUSION: rhTNK-tPA was non-inferior to rt-PA in the effect of improving recanalization of the infarct-related artery, a validated surrogate of clinical outcomes, among Chinese patients with acute STEMI. TRIAL REGISTRATION: www.ClinicalTrials.gov (No. NCT02835534).

Comparison of two bioelectrical impedance analysis devices with dual energy X-ray absorptiometry and magnetic resonance imaging in the estimation of body composition.

We compared a 4-limb bioelectrical impedance analysis (BIA) system, HBF 359 (Omron), and a 2-limb foot-to-foot device, BC 532 (Tanita), with the standard dual energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI) methods for the measurement of body fat percentage (BF), skeletal muscle mass percentage (SMM, or fat-free mass [FFM] for BC 532), and visceral fat level (VF). Body composition was measured in 200 healthy volunteers (100 men and 100 women, mean age 48 years) by HBF 359 and BC 532 and by DXA and MRI. The agreement was assessed by correlation analysis and paired t-test. The correlation coefficients between BIA and DXA or MRI ranged from 0.71 to 0.89 for BF, SMM, and VF by HBF 359 and from 0.77 to 0.90 for BF, FFM, and VF by BC 532 in all subjects and in men and women separately (p < 0.001 for all). Compared with DXA, HBF 359 significantly (p < 0.001) underestimated BF by -5.8% in men and -9.6% in women. Compared with MRI, the corresponding underestimatons (negative) or overestimations (positive) by HBF 359 in men and women were, respectively, +1.9% (p = 0.02) and +1.7% (p = 0.10) for SMM, and +13.3% (p < 0.001) and -8.5% (p = 0.006), for VF. The corresponding values by BC 532 in men and women were -10.7 and -6.2% for BF, -1.4 and -2.5% for FFM, and +20.4 and -18.0% for VF. The BIA devices are accurate in the estimation of body composition, especially skeletal muscle mass or FFM.

ABCG1 is Expressed in an LXR-Independent Manner in Patients with Type 2 Diabetes Mellitus.

BACKGROUND: Patients with type 2 diabetes mellitus have a high cardiovascular risk due, in part, to abnormalities of high-density lipoprotein mediated cholesterol efflux. The ATP-binding cassette A1 and G1 play a pivotal role in the regulation of cholesterol efflux. However, the regulation of these transporters in type 2 diabetes mellitus remains obscure. OBJECTIVES: This study aimed to investigate the expression of ATP-binding cassette A1 and G1 and their regulation by Liver X receptors in monocyte-derived macrophages in type 2 diabetes mellitus, and to determine whether the alteration of these transporters might affect cholesterol efflux from macrophages. METHODS: Blood was collected from type 2 diabetic patients and healthy controls. Peripheral monocytes were differentiated into macrophages. Quantitative real-time PCR, western blots, and cholesterol efflux assays were performed. The Liver X receptor and Liver X receptor element complex in the ATP-binding cassette G1 gene promoter were detected by electrophoretic mobility supershift assay. RESULTS: Macrophage ATP-binding cassette G1 expression and high density lipoproteininduced cholesterol efflux were significantly reduced in type 2 diabetic patients. However, the mRNA expression of ATP-binding cassette G1 in type 2 diabetic patients was not inhibited by Liver X receptor siRNA and the Liver X receptor- Liver X receptor element complexes remain unchanged similarly. CONCLUSION: The study suggested that the expression of ATP-binding cassette G1 and high density lipoprotein-induced cholesterol efflux in macrophages were reduced in type 2 diabetes mellitus. Impairment of cholesterol efflux and ATP-binding cassette G1 gene expression in type 2 diabetes mellitus might be regulated by a Liver X receptorindependent pathway.

Preoperative myocardial fibrosis is associated with worse survival after alcohol septal ablation in patients with hypertrophic obstructive cardiomyopathy: A delayed enhanced cardiac magnetic resonance study.

Background: Prior studies have shown that myocardial fibrosis can be detected by late gadolinium enhancement (LGE) of cardiac magnetic resonance (CMR) and might be associated with higher mortality risk in hypertrophic cardiomyopathy (HCM). The objective of this study was to examine the prognostic utility of CMR in patients with hypertrophic obstructive cardiomyopathy (HOCM) undergoing alcohol septal ablation (ASA). Materials and methods: We conducted a retrospective study which consisted of 183 consecutive patients with symptomatic drug-refractory HOCM who underwent CMR for assessment of myocardial fibrosis before ASA. The cardiovascular disease related survival was evaluated according to LGE-CMR status. Results: The cohort comprised 74 (40.4%) women with a mean age of 51 ± 8 years. Preoperative myocardial fibrosis was detected in 148 (80.9%) patients. After a median of 6 years (range 2-11 years) follow-up, adverse clinical events occurred in 14 (7.7%) patients. Multivariate-adjusted Cox regression analyses revealed that age [hazard ratio (HR) 1.142 (1.059-1.230), p = 0.001] and LGE [HR 1.170 (1.074-1.275), p < 0.001] were independent predictors of cardiovascular mortality during follow-up. Conclusion: Preoperative myocardial fibrosis measured by LGE-CMR was an independent predictor of increased adverse clinical outcomes in patients with HOCM undergoing ASA and could be used for the pre-operative evaluation of risk stratification and long-term prognosis after ASA in these patients.

Sex-related differences in left ventricular remodeling and outcome after alcohol septal ablation in hypertrophic obstructive cardiomyopathy: insights from cardiovascular magnetic resonance imaging.

BACKGROUND: Alcohol septal ablation (ASA) has been proven to reverse left ventricular (LV) remodeling in hypertrophic cardiomyopathy (HCM). However, there are no studies on the effect of sex on LV remodeling after ASA. We aimed to investigate whether sex differences affect the process of LV remodeling and outcome after ASA. METHODS: A total of 107 patients with obstructive HCM (54 men and 53 women, mean age 51 ± 8 years) were recruited. Cardiovascular magnetic resonance (CMR) was performed at baseline and 16 months after ASA. The extent of late gadolinium enhancement (LGE) was measured. RESULTS: Women had a higher indexed LV mass and smaller indexed LV end-systolic volumes than men at the time of ASA. After ASA, both men and women exhibited a regression of LV mass, and the percentage of mass regression was greater in men than women (15.3% ± 4.3% vs. 10.7% ± 1.8%, p < 0.001). In multivariable analysis, male sex, higher reduction of LV outflow tract (LVOT) gradient and lower baseline LV mass index were independently associated with greater LV mass regression after ASA. Kaplan-Meier analysis showed significantly higher cardiovascular events in women than in men (p = 0.015). Female sex [hazard ratio (HR) 3.913, p = 0.038] and LV mass preablation (HR, 1.019, p = 0.010) were independent predictors of cardiovascular outcomes. CONCLUSIONS: Males with HCM had favorable reverse remodeling with greater LV mass regression post-ASA than female patients. This favorable LV reverse remodeling might provide a mechanistic explanation for the survival advantage in men.

Comparisons of body-composition prediction accuracy: a study of 2 bioelectric impedance consumer devices in healthy Chinese persons using DXA and MRI as criteria methods.

We compared the accuracy of body-composition estimation for 2 commercial single-frequency bioelectric impedance analysis (BIA) devices in 200 healthy Chinese adults using magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry (DXA) as criterion methods. We evaluated the fat mass percentage (%FM), skeletal muscle mass percentage (%SM), or total-body bone-free lean mass percentage (%TBBLM), and level of visceral fat mass (VF(level)) using the Omron HBF-359 (SF-BIA8) and Tanita BC-532 (SF-BIA4) BIA devices, MRI, and DXA. Both devices showed a similarly high correlation with DXA for %FM prediction (r=0.89 for SF-BIA8 and 0.90 for SF-BIA4) and with MRI and DXA for %SM and %TBBLM prediction (r=0.85 for SF-BIA8 and 0.89 for SF-BIA4). There were small but significant biases in all body-composition parameter evaluations except for %SM assessed by the SF-BIA8. Both the SF-BIA8 and SF-BIA4 provided small, insignificant mean biases but wide limits of agreement with MRI for VF(level) assessments. Both BIA devices can relatively accurately predict %FM and %SM in healthy Chinese adults. The SF-BIA8 is suitable for individual prediction of %SM, whereas the SF-BIA8 is required to eliminate systematic errors in this population by improving population-specific prediction equations from height, weight, and age to increase estimation accuracy.

Characteristics and long-term mortality of patients with ST-elevation or non-ST-elevation myocardial infarction after orthopaedic surgery.

OBJECTIVE: To investigate the clinical characteristics and long-term mortality of patients with ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) after orthopaedic surgery. METHODS: This retrospective, single-centre study enrolled patients that underwent inpatient orthopaedic surgery from 2009 to 2017 in Beijing Jishuitan Hospital. The patients were screened for a cardiac troponin I elevation and fulfilled the Fourth Universal Definition of Myocardial Infarction within 30 days of surgery. RESULTS: A total of 180 patients that developed perioperative myocardial infarction (MI) were included in the study. Among them, 14 patients (7.8%) were classified as STEMI, and 166 (92.2%) had NSTEMI. Compared with those with NSTEMI, STEMI patients had significantly higher 30-day and long-term mortality rates (50.0% versus 5.4%; 71.4% versus 22.3%; respectively). Multivariate Cox regression model analysis among the entire cohort demonstrated that STEMI (hazard ratio [HR] 5.78, 95% confidence interval [CI] 2.50, 13.38) and prior MI (HR 2.35, 95% CI 1.02, 5.38) were the most significant independent predictors of long-term mortality. CONCLUSION: Perioperative MI after orthopaedic surgery was associated with a high mortality rate. STEMI was independently associated with a significant increase in short- and long-term mortality.

Azelnidipine and amlodipine: a comparison of their effects and safety in a randomized double-blinded clinical trial in Chinese essential hypertensive patients.

The purpose of this study is to compare the effects and safety of azelnidipine and amlodipine in Chinese essential hypertensive patients. Patients were randomized to receive administration of azelnidipine 8-16 mg/day or amlodipine 2.5-5 mg/day for 8 weeks. The blood pressure and pulse rate were evaluated in an outpatient clinic and by ambulatory blood pressure monitoring. There were 220 patients enrolled to the study. The blood pressure in both groups was decreased significantly (P < 0.001). Compared with amlodipine, the patients received azelnidipine had better response in systolic blood pressure (SBP) and diastolic blood pressure (DBP) (P < 0.01). No significant changes of pulse rate were observed in either group. For the ambulatory blood pressure monitoring, both drugs had stable anti-hypertensive effects over 24 h. The trough/peak ratios of DBP for the azelnidipine and amlodipine groups were, respectively, 46% and 40%. Adverse events occurred at 7.3% and 10.0%, respectively in the azelnidipine and amlodipine groups (P = 0.485). Headache and dizziness were observed at an incidence of more than 1% in both groups. Once-daily administration of azelnidipine effectively controlled blood pressure and had a stable action over 24 h. Azelnidipine had good safety and compliance similar to amlodipine.

Sex differences in the association of abdominal adipose tissue and anthropometric data with untreated hypertension in a Chinese population.

BACKGROUND: There are inconsistent interpretations of the interrelationship of adiposity, anthropometric indices, and blood pressure (BP) in hypertensive patients. Additionally, whether these relationships differ between sexes is unknown. We aimed to elucidate the associations of adiposity indices measured using quantitative computed tomography (QCT) with BP and hypertension and to determine the effect of sex on the interrelationship of these parameters in a Chinese population. METHODS: Abdominal adipose fat, including the visceral adipose tissue (VAT) area and subcutaneous adipose tissue (SAT) area, was measured by QCT in 1488 patients (514 men, 974 women). Body mass index (BMI), waist circumference (WC), hip circumference (HC), and systolic (SBP) and diastolic BP (DBP) were measured. Pearson correlation coefficients, multivariate analyses, and receiver operating characteristic (ROC) curves were used to assess the relationship and potential of adiposity indices to BP and risk of hypertension within sex groups. RESULTS: Men had significantly greater VAT area but less SAT area than women in hypertensive group. VAT, SAT, and WC were more highly correlated with SBP in men than in women. After controlling for body weight, height, and age, VAT area and WC were positively associated with SBP (VAT: ß = 0.309, p < 0.001; WC: ß = 0.148, p = 0.001) and DBP (VAT: ß = 0.099, p = 0.034; WC: ß = 0.198, p = 0.001) in women. VAT area was positively associated with SBP (ß = 0.444, p < 0.001) and DBP (ß = 0.146, p = 0.021) in men. WC had a significant correlation with an increased risk of hypertension in women but a borderline association in men (p = 0.059) when adjusted for VAT area and SAT area. CONCLUSIONS: The association of abdominal adiposity with hypertension differs qualitatively by sex. WC may be an important determinant of hypertension and may be used for risk stratification for hypertension among Chinese individuals.

Clinical characterization and outcome of prolonged heart rate-corrected QT interval among children with syndactyly.

Prolonged heart rate-corrected QT (QTc) interval is an independent risk factor for sudden cardiac death, which is the hallmark of Timothy syndrome (TS). There are little data on children with syndactyly and QTc prolongation.To evaluate the characteristics and long-term outcomes in children with syndactyly, and to attempt to identify TS in patients with syndactyly and QTc prolongation.This is a retrospective case-control study of children with syndactyly who visited Beijing Jishuitan Hospital between July 2003 and February 2013. The patients with prolonged QTc intervals are matched 1:4 with patients without prolongation. Genetic testing of the CACNA1C gene is routinely performed in patients with QTc prolongation.The mean age at admission is 3.4 ±â€Š2.3 years. Compared with the normal QTc group, those with QTc prolongation showed higher frequencies of congenital heart disease (11.8% vs 1.5%, P = .042), mental retardation and facial dysmorphia (11.8% vs 0, P = .004), and T wave alternans (23.5% vs 4.4%, P = .01). In the multivariable analysis, only T wave alternans (OR = 10.61, 95%CI: 1.39-81.16, P = .023) is independently associated with QTc prolongation in patients with syndactyly. One child with QTc prolongation had a mutation in the CACNA1C gene. No patients with prolonged QTs interval met the threshold for TS.Children with syndactyly and prolonged QTc interval had more multisystem diseases and electrocardiography abnormalities. T wave alternans is independently associated with QTc prolongation in patients with syndactyly.

[Mechanical analysis on a new type of biodegradable magnesium-alloy stent].

Biodegradable magnesium-alloy stents have been employed in animal experiments and clinical researches in recent years. Magnesium-alloy stents have been reported to be biocompatible, and degradable due to corrosion after being implanted into blood vessel. However, magnesium alloy is brittle compared with stainless steel. This may cause strut break under large deformation. In this paper, a finite element model of magnesium-alloy stent was set up, with reference to pictures from Biotronik Corporation, to simulate the expanding and bending processes. The results of analysis show that the maximum strain during expanding reaches 20%, being greater than the elongation limit of the commercially available magnesium alloys. Therefore, to avoid strut breakage during expanding, the magnesium alloys should be custom-made. The plasticity of the material should be improved by grain refinement processes before practicable magnesium-alloy stents could be developed.

Recombinant human TNK tissue-type plasminogen activator (rhTNK-tPA) versus alteplase (rt-PA) as fibrinolytic therapy for acute ST-segment elevation myocardial infarction (China TNK STEMI): protocol for a randomised, controlled, non-inferiority trial.

AIM: To evaluate the efficacy and safety of recombinant human TNK tissue-type plasminogen activator (rhTNK-tPA) in lowering major adverse cardiovascular and cerebrovascular events (MACCEs) in Chinese acute ST-segment elevation myocardial infarction (STEMI) patients. METHODS AND ANALYSIS: The study is designed as a multicentre, randomised, controlled non-inferiority phase IV trial with balanced randomisation (1:1) in patients with STEMI. The planned sample size is 6200 participants (or 3100 per arm). Participants with STEMI will be randomised to receive either rhTNK-tPA or alteplase (rt-PA), with stratification by research centre, age and the time from symptom onset to randomisation. All patients will receive concomitant antiplatelet and anticoagulant therapy before fibrinolytic therapy. The participants assigned to the intervention group will receive an intravenous bolus of 16 mg rhTNK-tPA, while those assigned to the control group will receive an intravenous bolus of 8 mg rt-PA followed by 42 mg infusion over 90 mins. Other medications can also be administered at the discretion of the cardiologists in charge. All participants will be followed up for the primary study endpoint, the occurrence of MACCEs within 30 days after fibrinolytic therapy, which is defined as all-cause mortality, non-fatal re-infarction, non-fatal stroke, percutaneous coronary intervention (PCI) due to thrombolysis failure, and PCI due to reocclusion. Both intention-to-treat and per-protocol analyses will be done for the primary analyses. ETHICS AND DISSEMINATION: The study procedures and informed consent form were approved by all participating hospitals. The results will be disseminated in peer review journals and academic conferences. This multicentre randomised controlled trial will provide high-quality data about the efficacy and safety of rhTNK-tPA and, once approved, its easier use should help improve the application of reperfusion therapy and hence the treatment outcomes of STEMI patients. TRIAL REGISTRATION NUMBER: NCT02835534.

Using a low-sodium, high-potassium salt substitute to reduce blood pressure among Tibetans with high blood pressure: a patient-blinded randomized controlled trial.

OBJECTIVES: To evaluate the effects of a low-sodium and high-potassium salt-substitute on lowering blood pressure (BP) among Tibetans living at high altitude (4300 meters). METHOD: The study was a patient-blinded randomized controlled trial conducted between February and May 2009 in Dangxiong County, Tibetan Autonomous Region, China. A total of 282 Tibetans aged 40 or older with known hypertension (systolic BP≥140 mmHg) were recruited and randomized to intervention (salt-substitute, 65% sodium chloride, 25% potassium chloride and 10% magnesium sulfate) or control (100% sodium chloride) in a 1: 1 allocation ratio with three months' supply. Primary outcome was defined as the change in BP levels measured from baseline to followed-up with an automated sphygmomanometer. Per protocol (PP) and intention to treat (ITT) analyses were conducted. RESULTS: After the three months' intervention period, the net reduction in SBP/DBP in the intervention group in comparison to the control group was -8.2/-3.4 mmHg (all p<0.05) in PP analysis, after adjusting for baseline BP and other variables. ITT analysis showed the net reduction in SBP/DBP at -7.6/-3.5 mmHg with multiple imputations (all p<0.05). Furthermore, the whole distribution of blood pressure showed an overall decline in SBP/DBP and the proportion of patients with BP under control (SBP/DBP<140 mmHg) was significantly higher in salt-substitute group in comparison to the regular salt group (19.2% vs. 8.8%, p = 0.027). CONCLUSION: Low sodium high potassium salt-substitute is effective in lowering both systolic and diastolic blood pressure and offers a simple, low-cost approach for hypertension control among Tibetans in China. TRIAL REGISTRATION: ClinicalTrials.gov NCT01429246.

Can electronic sphygmomanometers be used for measurement of blood pressure at high altitudes?

OBJECTIVE: Validated automated oscillometric sphygmomanometers have been recommended by clinical guidelines to replace mercury sphygmomanometers. No studies have been conducted to evaluate whether these validated devices designed for use at normal altitude are also suitable at high altitudes. METHODS: In Dangxiong County in Tibet, 4300 m above sea level, two trained cardiologists used standardized protocols to measure the blood pressure (BP) of 129 adults aged between 19 and 69 years three times in a quiet room. The electronic sphygmomanometer was connected to the mercury sphygmomanometer by a 'Y,' or a three-way air-control valve, and the electronic device providing the pressure. This allowed simultaneous and blinded BP measurements with both instruments. RESULTS: The mean systolic BP measured by the electronic sphygmomanometer (124.67 ± 20.39 mmHg) was significantly higher than the BP reported by the mercury device (118.91 ± 20.56 mmHg; P < 0.001), whereas the diastolic BP measured by electronic (76.54 ± 12.63 mmHg) and mercury (76.95 ± 13.86 mmHg) sphygmomanometers showed no significant difference (P = 0.228). There was a strong linear relationship between readings from the two instruments, with correlation coefficients for systolic and diastolic BP of 0.97 and 0.96, respectively. Bland-Altman plots showed a general consistency between the two instruments for both systolic and diastolic BP. The systolic BP values, calibrated by subtracting the mean difference, were not inferior to those obtained from linear regression equations. CONCLUSION: This first explorative study conducted at a high altitude demonstrated that the electronic sphygmomanometer can provide an accurate direct measurement of diastolic BP; however, a simple calibration is required for systolic BP.

Prevalence, awareness, treatment, and control of hypertension among herdsmen living at 4,300 m in Tibet.

BACKGROUND: Studies on blood pressure (BP) in high-altitude areas are scarce and the results are controversial. Tibetans live in regions at high altitudes, and data on the prevalence of hypertension in this population is not currently well known. METHODS: All Tibetans aged 40 years and older living in the township of Yangbajing (4,300 m) in Tibet, China were invited to participate in the 2009 survey. BP was measured with electronic sphygmomanometers (calibrated by the results of a previous study). Histories of hypertension and medication use were collected through face-to-face interviews. Hypertension was defined as systolic BP (SBP) ≥140 mm Hg and/or diastolic BP (DBP) ≥90 mm Hg, or antihypertensive medication use in the past 2 weeks. RESULTS: A total of 701 adults (aged 40-89, 42.9% male, 94.9% herdsmen) were recruited. The mean (s.d.) SBP/DBP was 146.6 (31.3)/92.0 (15.7) mm Hg and the prevalence of hypertension was 55.9%. Of note, 61.2% of those with hypertension had stage 2 hypertension (SBP ≥160 or DBP ≥100 mm Hg). At age 70 years and older, the mean (s.d.) SBP/DBP were 182.8 (30.9)/102.6 (13.4) mm Hg. Among those with hypertension (n = 392), only 19.9% were aware of their condition, 2.6% were taking medication, and only one participant had controlled BP. CONCLUSION: According to our survey in Yangbajing, Tibetan adults aged 40 years and older living at high altitudes had high BP and prevalence of hypertension with low awareness, treatment, and control. Future studies are needed to clarify the association between BP, altitude, and other possible causes.