Shenshen Li

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.

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

Rational and design of a stepped-wedge cluster randomized trial evaluating quality improvement initiative for reducing cardiovascular events among patients with acute coronary syndromes in resource-constrained hospitals in China.

BACKGROUND Acute coronary syndromes (ACSs) are a major cause of morbidity and mortality, yet effective ACS treatments are frequently underused in clinical practice. Randomized trials including the CPACS-2 study suggest that quality improvement initiatives can increase the use of effective treatments, but whether such programs can impact hard clinical outcomes has never been demonstrated in a well-powered randomized controlled trial. DESIGN The CPACS-3 study is a stepped-wedge cluster-randomized trial conducted in 104 remote level 2 hospitals without PCI facilities in China. All hospitalized ACS patients will be recruited consecutively over a 30-month period to an anticipated total study population of more than 25,000 patients. After a 6-month baseline period, hospitals will be randomized to 1 of 4 groups, and a 6-component quality improvement intervention will be implemented sequentially in each group every 6months. These components include the following: establishment of a quality improvement team, implementation of a clinical pathway, training of physicians and nurses, hospital performance audit and feedback, online technical support, and patient education. All patients will be followed up for 6months postdischarge. The primary outcome will be the incidence of in-hospital major adverse cardiovascular events comprising all-cause mortality, myocardial infarction or reinfarction, and nonfatal stroke. CONCLUSIONS The CPACS-3 study will be the first large randomized trial with sufficient power to assess the effects of a multifaceted quality of care improvement initiative on hard clinical outcomes, in patients with ACS.

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

ObjectiveValidated 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. MethodsIn 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. ResultsThe 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. ConclusionThis 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.

Impact of Prior Use of Four Preventive Medications on Outcomes in Patients Hospitalized for Acute Coronary Syndrome--Results from CPACS-2 Study

Background It is widely reported that long-term use of four preventive medications (antiplatelet agents, angiotensin converting enzyme inhibitor / angiotensin receptor blocker, statin and beta-blockers) reduce the risk of subsequent acute coronary syndromes (ACS). It is unclear whether these four medications benefit patients who develop ACS despite its use. Methods and Results Logistic regression and propensity-score was applied among 14790 ACS patients to assess the association between prior use of four preventive medications and in-hospital outcomes including severity of disease at presentation (type of ACS, systolic blood pressure <90 mmHg, and heart rate> = 100 beats/min), complicating arrhythmia and major adverse cardiovascular events (MACEs, including all deaths, non-fatal myocardial infarction or re-infarction, and non-fatal stroke). Prior use of each of the four medications was significantly associated with less severity of disease (ORs ranged from 0.40 to 0.82, all P<0.05), less arrhythmia (ORs ranged from 0.45 to 0.64, all P<0.05), and reduced risk of MACEs (ORs ranged from 0.59 to 0.73, all P<0.05) during hospitalization. Multiple variable-adjusted ORs of MACEs were 0.77, 0.67, 0.48 and 0.59 respectively in patients with 1, 2, 3 and 4 medications in comparison with patients with none, and other clinical outcomes showed the same trend (P for trend < 0.05). Conclusions Among ACS patients in our study, those with prior use of four preventive medications presented with less disease severity, developed less arrhythmia and had a lower risk of in-hospital MACEs. The value of taking these medications may beyond just preventing occurrence of the disease.

Prescription of statins at discharge and 1-year risk of major clinical outcomes among acute coronary syndromes patients with extremely low LDL-cholesterol in clinical pathways for acute coronary syndr

The aim of this study was to investigate statin description on discharge and the benefit on the long‐term outcomes in acute coronary syndromes (ACS) patients with very low baseline LDL‐cholesterol (LDL‐c).

I-CARE randomized clinical trial integrating depression and acute coronary syndrome care in low-resource hospitals in China: Design and rationale

Depression and acute coronary syndromes (ACS) are both common public health challenges. Patients with ACS often develop depression, which in turn adversely affects prognosis. Low-cost, sustainable, and effective service models that integrate depression care into the management of ACS patients to reduce depression and improve ACS outcomes are critically needed. Integrating Depression Care in ACS patients in Low Resource Hospitals in China (I-CARE) is a multicenter, randomized controlled trial to evaluate the efficacy of an 11-month integrated care (IC) intervention compared to usual care (UC) in management of ACS patients. Four thousand inpatients will be recruited and then randomized in a 1:1 ratio to an IC intervention consisting of nurse-led risk factor management, group-based counseling supplemented by individual problem-solving therapy, and antidepressant medications as needed, or to UC. The primary outcomes are depression symptoms measured by the Patient Health Questionnaire-9 at 6 and 12 months. Secondary endpoints include anxiety measured by the Generalized Anxiety Disorder-7; quality of life measured by the EQ-5D at 6 and 12 months; and major adverse events including the combined end point of all-cause death, suicide attempts, nonfatal myocardial infarction, nonfatal stroke, and all-cause rehospitalization at yearly intervals for a median follow-up of 2 years. Analyses of the cost-effectiveness and cost-utility of IC also will be performed. I-CARE trial will be the largest study to test the effectiveness of an integrated care model on depression and cardiovascular outcomes among ACS patients in resource-limited clinical settings.

Factors attributed to the higher in-hospital mortality of ST elevation myocardial infarction patients admitted during off-hour in comparison with those during regular hour.

Background In-hospital mortality of patients with ST elevation myocardial infarction (STEMI) admitted during off-hour was reported higher than those admitted during regular hour, but which factors cause the difference remains largely unknown though the difference in medical resources was often accused. Methods and results This registry-based study recruited 7456 STEMI patients prospectively from 99 level two hospitals across China. Generalized linear mixed models were applied to quantify the risk of in-hospital death attributed to admission time and the explainers of its change, accounting for the clustering of patients within hospitals. There were 45.2% patients admitted during regular hour and 54.8% during off-hour. In-hospital mortality was 7.0% for patients admitted during regular hour and 8.3% for those during off-hour (p<0.05). Generalized linear mixed models adjusting for age, gender and education showed that patients’ disease severity at admission and medical treatments received after admission could explain the risk difference attributed to admission time by 55% and 20%, respectively. After all factors accounted, the residual relative risk difference left only 6% (adjusted OR = 0.94) and became no longer significant. Conclusions The regular-and-off-hour mortality difference exists among STEMI patients in Chinese level two hospitals, which could be attributed primarily to disease severity at admission and secondly to the poorer medical treatments. These results call for public attention to the more severity of STEMI patients admitted during off-hour in addition to improving medical resources for STEMI at off-hour.