Title: Remote Ischemic Conditioning Before Hospital Admission, as a Complement to Angioplasty, and Effect on Myocardial Salvage in Patients With Acute Myocardial Infarction: A Randomised Trial
Topic: Interventional Cardiology
Date Posted: 4/15/2010
Author(s): Bшtker HE, Kharbanda R, Schmidt MR, et al.
Citation: Lancet 2010;375:727-734.
Clinical Trial: yes
Study Question: Does remote ischemic conditioning, done before primary percutaneous coronary intervention (PPCI), increase myocardial salvage?
Methods: A total of 333 consecutive adult patients with a suspected first acute myocardial infarction were randomly assigned in a 1:1 ratio by computerized block randomization to receive PPCI with (n = 166 patients) versus without (n = 167) remote conditioning (intermittent arm ischemia through four cycles of 5-minute inflation and 5-minute deflation of a blood-pressure cuff). Allocation was concealed with opaque sealed envelopes. Patients received remote conditioning during transport to the hospital, and PPCI in the hospital. The primary endpoint was myocardial salvage index at 30 days after PPCI, measured by myocardial perfusion imaging as the proportion of the area at risk salvaged by treatment; analysis was per protocol.
Results: Eighty-two patients were excluded on arrival at the hospital because they did not meet inclusion criteria, 32 were lost to follow-up, and 77 did not complete the follow-up with data for salvage index. Median salvage index was 0.75 (interquartile range, 0.50-0.93; n = 73) in the remote conditioning group versus 0.55 (0.35-0.88, n = 69) in the control group, with median difference of 0.10 (95% confidence interval [CI], 0.01-0.22; p = 0.0333); mean salvage index was 0.69 (standard deviation, 0.27) versus 0.57 (0.26), with mean difference of 0.12 (95% CI, 0.01-0.21; p = 0.0333). Major adverse coronary events were death (n = 3 per group), reinfarction (n = 1 per group), and heart failure (n = 3 per group).
Conclusions: The authors concluded that remote ischemic conditioning before hospital admission increases myocardial salvage, and has a favorable safety profile.
Perspective: The current study shows that remote ischemic conditioning induced by intermittent upper-arm ischemia and done before PPCI, can attenuate reperfusion injury in patients with evolving myocardial infarction, thereby resulting in increased myocardial salvage. This protective effect seemed to be strongest in patients with totally occluded vessels and with infarcts in the left anterior descending artery, both of which were associated with almost double the area at risk. The effectiveness of remote conditioning after onset of target-organ ischemia could have implications for myocardial infarction and stroke treated with thrombolytics, but needs to be tested in large-scale clinical trials. Debabrata Mukherjee, M.D., F.A.C.C.
Title: Association Between Admission Supine Systolic Blood Pressure and 1-Year Mortality in Patients Admitted to the Intensive Care Unit for Acute Chest Pain
Topic: Prevention/Vascular
Date Posted: 4/14/2010
Author(s): Stenestrand U, Wijkman M, Fredrikson M, Nystrom FH.
Citation: JAMA 2010;303:1167-1172.
Clinical Trial: No
Study Question: What is the relation between long-term mortality and admission blood pressure (BP) in patients admitted to the medical intensive care unit (ICU) for acute chest pain?
Methods: The authors evaluated the RIKS-HIA (Registry of Information and Knowledge About Swedish Heart Intensive Care Admissions) to analyze the association between long-term mortality and supine admission systolic BP in 119,151 patients who were treated at any Swedish ICU for the symptom of chest pain from 1997 through 2007. Patients were divided into quartiles of systolic BP Q1, <128 mm Hg; Q2, from 128 to 144 mm Hg; Q3, from 145 to 162 mm Hg; and Q4, ≥163 mm Hg. The main outcome measure was all-cause mortality.
Results: Mean follow-up was 2.47 years. The highest mortality was seen in the first quartile and the lowest in the fourth quartile. After adjusting for age, sex, smoking, diastolic BP, use of antihypertensive medication at admission and discharge, and use of lipid-lowering and antiplatelet medication at discharge, patients in the fourth quartile had the lowest 1-year mortality compared with quartile 2 (hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.72-0.80), while the hazard was worse in quartile 1 (HR, 1.46; 95% CI, 1.39-1.52) and intermediate for Q3 (HR, 0.83; 95% CI, 0.79-0.87). The better prognosis in Q4 compared with Q2 was maintained in patients with a final diagnosis of angina or myocardial infarction (HR, 0.75; 95% CI, 0.71-0.80).
Conclusions: A higher systolic BP at admission in patients admitted to the ICU is associated with a better long-term survival.
Perspective: The association between a higher BP and better short-term outcome in patients with chest pain has been previously established (Khot, JAMA 2003). This study suggests that this association is valid for intermediate-term mortality. While high BP may be of prognostic importance in large hospitalized populations, its direct implication for patient care is somewhat unclear. Poorly controlled hypertension remains a major public health problem, and the results of this study should not distract from the need to ensure optimal BP control in all patients. Hitinder S. Gurm, M.B.B.S., F.A.C.C.