P6428The waist-to-body mass index ratio is a better predictor for cardiovascular outcome in patients with established atherosclerotic cardiovascular disease - No u-shaped phenomenon

Background

Many studies have observed an “obesity paradox” in patients with established atherosclerotic cardiovascular disease (ASCVD), in which the body mass index (BMI)-mortality curve is U-shaped.

Purpose

To search a better anthropometric parameter to predict the cardiovascular events in patients with ASCVD.

Methods

The study was conducted from the Taiwanese Secondary Prevention for patients with AtheRosCLErotic disease (T-SPARCLE) Registry. Adult patients with stable ASCVD were enrolled. The primary composite endpoint of this study is the time of the first major cardiovascular event, defined as cardiovascular death, nonfatal myocardial infarction or stroke, or cardiac arrest with resuscitation. Dose response association between primary outcome events and various traditional anthropometric parameters and a new parameter, the waist-to-BMI ratio, was examined using the Cox proportional hazards regression model. We used restricted cubic spline regression to investigate the potential nonlinear relationship between each anthropometric measure and primary outcome events.

Results

A total of 6921 patients with ASCVD were included in this analysis, and were followed up for a median of 2.5 years. Multivariable Cox proportional hazards regression showed a significant positive association between the waist-to-BMI ratio and the primary outcome events (adjusted hazard ratio 1.67, 95% CI 1.12–2.49, p=0.01). Other traditional anthropometric parameters, such as BMI, weight, waist and waist-hip ratio, did not showed significant associations (p=0.10, 0.31, 0.90, and 0.52, respectively). In the restricted cubic spline regression, the positive dose response association between the primary outcome and the waist-to-BMI ratio persisted across all the waist-to-BMI ratio, and was non-linear (the likelihood ratio test for nonlinearity was statistically significant, p<0.001) with a much steeper increase in the major cardiovascular event for the waist-to-BMI ratio >3.6 cm m2/kg.

Dose response curve of waist/BMI ratio

Conclusion

This study found the waist-to-BMI ratio to be a better predictor for major adverse cardiovascular events in established ASCVD patients than other traditional anthropometric parameters.

In vivo and real-time measurement of magnetic nanoparticles distribution in animals by scanning SQUID biosusceptometry for biomedicine study

Magnetic nanoparticles have been widely applied to biomagnetism, such as drug deliver, magnetic labeling, and contrast agent for in vivo image, etc. To localize the distribution of these magnetic particles in living organism is the first important issue to confirm the effects of magnetic nanoparticles and also evaluate the possible untoward effects. In this study, a scanning high T(c) rf-SQUID superconducting quantum interference devices (SQUIDs) biosusceptometry, composed of static SQUID unit and scanning coil sets, is developed for biomedicine study with the advantages of easy operation and unshielded environment. The characteristics tests showed that the system had the low noise of 8 pT/Hz at 400 Hz and the high sensitivity with the minimum detectable magnetization around 4.5 × 10(-3) EMU at distance of 13 mm. A magnetic nanoparticle detection test, performed by ex vivo scanning of the magnetic fluids filled capillary under swine skin for simulation of blood vessels in living bodies, confirmed that the system is feasible for dynamic tracking of magnetic nanoparticles. Based on this result, we performed further studies in rats to clarify the dynamic distribution of magnetic nanoparticle in living organism for the pharmacokinetics analysis like drug delivers, and propose the possible physiological metabolism of intravenous magnetic nanoparticles.

A double-blind comparison of the efficacy and tolerability of telmisartan 40-80 mg vs. losartan 50-100 mg in Taiwanese hypertensive patients

A multicentre, randomised, double-blind, double-dummy, parallel-group, dose-titration study was conducted to determine the efficacy and tolerability of telmisartan 40-80 mg once daily compared with losartan 50-100 mg once daily in 180 Taiwanese patients with mild-to-moderate essential hypertension. After an initial 2-week placebo run-in phase, patients were randomised in a double-blind, double-dummy fashion to receive either telmisartan 40 mg or losartan 50 mg. If blood pressure control (diastolic blood pressure [DBP] <90 mmHg or > or = 10 mmHg reduction in DBP) was achieved after 4 weeks, the dose was maintained for the second 4 weeks of the active treatment phase; if not, the dose was doubled to telmisartan 80 mg or losartan 100 mg, respectively, for the second 4 weeks of double-blind treatment. Telmisartan 40-80 mg (n = 86) was as effective as losartan 50-100 mg (n = 90) in reducing trough seated DBP (11.1 vs. 8.7 mmHg, p = 0.144), and was significantly more effective than losartan in reducing trough seated systolic blood pressure (SBP) (22.1 vs. 16.5 mmHg, p = 0.032) and standing SBP (21.0 vs. 16.3 mmHg, p = 0.033). Significantly fewer patients treated with telmisartan than those treated with losartan required uptitration after 4 weeks' treatment (32.6% vs. 61.5%, p = 0.001). Both telmisartan and losartan were well tolerated.

Dobutamine stress echocardiography compared with exercise thallium-201 single-photon emission computed tomography in detecting coronary artery disease-effect of exercise level on accuracy

Dobutamine stress echocardiography (DSE) and exercise thallium-201 single-photon emission computed tomography (SPECT) were compared for the accuracy in detecting coronary artery disease (CAD) in 51 consecutive patients. Twenty-six (group 1) of the 51 patients achieved adequate exercise end points, and 25 (group 2) did not. There were 38 patients with angiographically documented CAD. The overall sensitivity of DSE and thallium-201 SPECT in detecting CAD was 92 and 76% (p = NS), and the specificity was 77 and 77% (p = NS), respectively. The sensitivity of DSE is the same as that of SPECT in group 1 (90 vs. 90%; p = NS) and higher than that of SPECT in group 2 (94 vs. 61%; p < 0.05). In patients with CAD without a history of acute myocardial infarction or pathological Q wave on resting electrocardiogram, the sensitivity of DSE is the same as that of SPECT in group 1 (82 vs. 82%; p = NS) and also higher than that of SPECT in group 2 (90 vs. 40%; p = 0.03). The sensitivity in detecting individual coronary artery lesions with DSE and thallium-201 SPECT was not affected by the exercise level. The agreement between DSE and thallium SPECT in detecting patients with CAD was 88% in group 1 (kappa = 0.69; p < 0.001) and 76% in group 2 (kappa = 0.45; p = 0.01). The agreement in detecting vascular territories with ischemia was 68% in group 1 (kappa = 0.30; p < 0.01) and 75% in group 2 (kappa = 0.33; p < 0.001). The agreement in detecting vascular territories with a scar was 87% in group 1 (kappa = 0.55; p < 0.001) and 85% in group 2 (kappa = 0.44; p < 0.001). In conclusion, the sensitivity and specificity of DSE in detecting CAD are similar to that of thallium-201 SPECT with an exercise level > or =85% of the maximal predicted heart rate. However, in patients who cannot exercise adequately, DSE is more accurate than thallium SPECT. The agreement between DSE and thallium SPECT in detecting patients with CAD and identifying ischemia of individual vascular territories is also affected by the exercise level.

Localizing individual coronary artery obstructions with the dobutamine stress echocardiography

The diagnostic accuracy of detecting individual coronary artery lesions using dobutamine stress echocardiography was evaluated in 206 patients with clinical manifestations of agnina pectoris. The sensitivity, specificity, and accuracy in detecting individual coronary artery lesions was described. The sensitivity was higher in the single-vessel group than in the double- or triple-vessel group. Furthermore, the sensitivity of dobutamine stress echocardiography in localizing vascular territories was greater for proximal segment lesions than for distal segment lesions. The increment of total score and score index at peak dose did not reach statistical significance between the left main lesion and the double-vessel lesions of left anterior descending artery and left circumflex artery (4.88 +/- 1.44 vs. 3.79 +/- 0.39, nonsignificant; 0.83 +/- 0.25 vs. 0.54 +/- 0.06, nonsignificant). In conclusion, although dobutamine stress echocardiography is sensitive for diagnosing coronary artery disease, localizing individual coronary artery lesions is less sensitive for triple-vessel disease and distal lesions.