Ischemic postconditioning does not improve peripheral endothelial function in ST-segment elevation myocardial infarction patients.

The purpose of this study was to determine whether ischemic postconditioning (IPC) could improve peripheral endothelial function in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Of 102 patients randomly assigned to an IPC or standard protocol to study infarct size utilizing cardiovascular magnetic resonance imaging, 84 patients had peripheral endothelial function assessed with brachial ultrasound measures and peripheral arterial tonometry (PAT) during reactive hyperemia 3 days after PCI. Overall IPC was not associated with a smaller infarct size compared to controls, though there was a trend towards greater myocardial salvage with IPC. Patients randomized to IPC (n=43; age 56 ± 11 years; 85% male) and standard protocol (n=41; age 56 ± 10 years; 88% male) underwent endothelial function assessment. Flow mediated vasodilatation was not significantly greater in the IPC group than in the standard group (7.4 ± 4.9% versus 6.6 ± 4.0% respectively, p=0.40) nor was peak hyperemic velocity-time integral (78 ± 26 cm versus 71 ± 30 cm respectively, p=0.28). Similarly, the PAT hyperemic ratio was not significantly greater in the IPC group than in the standard group (2.0 ± 0.9 versus 1.8 ± 0.6 respectively, p=0.14). In conclusion, IPC did not improve early peripheral endothelial function in patients with STEMI undergoing primary PCI.

Absolute cardiovascular risk assessment using 'real world' clinic blood pressures compared to standardized unobserved and ambulatory methods: an observational study.

Clinic blood pressure (BP) is recommended for absolute cardiovascular disease (CVD) risk assessment. However, in 'real-world' settings, clinic BP measurement is unstandardised and less reliable compared to more rigorous methods but the impact for absolute CVD risk assessment is unknown. This study aimed to determine the difference in absolute CVD risk assessment using real-world clinic BP compared to standardised BP methods. Participants were patients (n = 226, 59 ± 15 years; 58% female) with hypertension referred to a BP clinic for assessment. 'Real-world' clinic BP was provided by the referring doctor. All participants had unobserved automated office BP (AOBP) and 24-h ambulatory BP monitoring (ABPM) measured at the clinic. Absolute CVD risk was calculated (Framingham) using systolic BP from the referring doctor (clinic BP), AOBP and ABPM, with agreement assessed by Kappa statistic. Clinic systolic BP was 18 mmHg than AOBP and daytime ABPM and 22 mmHg higher than 24-h ABPM (p < 0.001). Subsequently, absolute CVD risk scores using clinic BP were higher compared to AOBP, daytime ABPM and 24-h ABPM (10.4 ± 8.1%, 7.8 ± 6.4%, 7.8 ± 6.3%, and 7.3 ± 6.1%, respectively, P < 0.001). As a result, more participants were classified as high CVD risk using clinic BP (n = 89, 40%) compared with AOBP (n = 44, 20%) daytime ABPM (n = 38, 17%) and 24-h ABPM (n = 38, 17%) (p < 0.001) with weak agreement in risk classification (κ = 0.57[0.45-0.69], κ = 0.52[0.41-0.64] and κ = 0.55[0.43-0.66], respectively). Real-world clinic BP was higher and classified twice as many participants at high CVD risk compared to AOBP or ABPM. Given the challenges to high-quality BP measurement in clinic, more rigorous BP measurement methods are needed for absolute CVD risk assessment.

No cardioprotective benefit of ischemic postconditioning in patients with ST-segment elevation myocardial infarction.

BACKGROUND: Postconditioning is a potential cardioprotective strategy that has demonstrated conflicting and variable reductions in infarct size in human trials. OBJECTIVES: To determine whether postconditioning could increase the extent of myocardial salvage in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention (PPCI). METHODS: One hundred two patients (aged 57 ± 11 years; 88% male) were randomly assigned to a postconditioning or standard protocol. Cardiovascular magnetic resonance imaging was performed 3 days after PPCI to measure the volumetric extent of myocardial necrosis and the area at risk. RESULTS: With similar time-to-reperfusion (170 ± 84 minutes in the postconditioning group vs. 150 ± 70 minutes in the standard group, P = 0.22), the myocardial salvage index was not significantly different between the postconditioned group and the control group, averaging 42 ± 22% vs. 33 ± 21%, respectively (P = 0.08). Furthermore, postconditioning was not associated with a smaller infarct size compared to controls (13 ± 7 g/m(2) vs. 15 ± 8 g/m(2), respectively, P = 0.18). CONCLUSIONS: Postconditioning does not significantly increase myocardial salvage or reduce infarct size in patients with STEMI undergoing PPCI. However, the possibility of a more modest impact of postconditioning cannot be excluded with our sample size.

Identification of the Optimal Protocol for Automated Office Blood Pressure Measurement Among Patients With Treated Hypertension.

BACKGROUND: Automated office blood pressure (AOBP) involving repeated, unobserved blood pressure (BP) readings during one clinic visit is recommended for in-office diagnosis and assessment of hypertension. However, the optimal AOBP protocol to determine BP control in the least amount of time with the fewest BP readings is yet to be determined and was the aim of this study. METHODS: One hundred and eighty-nine patients (mean age 62.8 ± 12.1 years; 50.3% female) with treated hypertension referred to specialist clinics at 2 sites underwent AOBP in a quiet room alone. Eight BP measurements were taken starting immediately after sitting and then at 2-minute intervals (15 minutes total). The optimal AOBP protocol was defined by the smallest mean difference and highest intraclass correlation coefficient (ICC) compared with daytime ambulatory BP (ABP). The same BP device (Mobil-o-graph, IEM) was used for both AOBP and daytime ABP. RESULTS: Average 15-minute AOBP and daytime ABP were 134 ± 22/82 ± 13 and 137 ± 17/83 ± 11 mm Hg, respectively. The optimal AOBP protocol was derived within a total duration of 6 minutes from the average of 2 measures started after 2 and 4 minutes of seated rest (systolic BP: mean difference (95% confidence interval) 0.004(-2.21, 2.21) mm Hg, P = 1.0; ICC = 0.81; diastolic BP: mean difference 0.37(-0.90, 1.63) mm Hg, P = 0.57; ICC = 0.86). AOBP measures taken after 8 minutes tended to underestimate daytime ABP (whether as a single BP or the average of more than 1 BP reading). CONCLUSIONS: Only 2 AOBP readings taken over 6 minutes (excluding an initial reading immediately after sitting) may be needed to be comparable with daytime ABP.