Association between trajectories of systolic blood pressure and frailty outcome in middle-aged and older adults.

OBJECTIVES: The association between blood pressure and frailty outcome in the middle-aged and older population remains controversial. This study aimed to examine the relationship between trajectories of systolic blood pressure (SBP) and new-onset frailty. DESIGN: Cohort study with a 7-year follow-up. SETTING AND PARTICIPANTS: Data were derived from 4 waves (2011, 2013, 2015 and 2018) of the China Health and Retirement Longitudinal Study and 6168 participants aged ≥45 years were included in the study. METHODS: The frailty index (FI) was constructed based on 40 scored items, with FI ≥ 0.25 defined as frailty. We identified the 5-year trajectory of SBP by latent class trajectory modeling. The association between SBP trajectories and frailty was explored based on hazard ratios (HR) by four Cox proportional hazards models. Furthermore, we also investigated the relationship between mean SBP and systolic blood pressure variability (SBPV) and frailty. RESULTS: 6168 participants were included in this study with a mean age of 59 years. We identified five trajectories based on SBP, which are maintained low-stable SBP (T0), moderate-stable SBP (T1), remitting then increasing SBP (T2), increasing then remitting SBP (T3), and remaining stable at high SBP levels (T4). During the 7-year follow-up period, frailty outcome occurred in 1415 participants. After adjusting for other confounders, the two trajectories labeled "T2" and "T4" were associated with a higher risk of frailty compared with T0. In addition, elevated SBP and increased SBPV were associated with risk of frailty. CONCLUSIONS: Higher risk of frailty occurred in two trajectories, remitting then increasing and remaining stable at high SBP levels, were associated with a relatively higher risk of frailty.

64-slice CT angiography for the detection of functionally significant coronary stenoses: comparison with stress myocardial perfusion imaging.

OBJECTIVE: To evaluate the accuracy of 64-slice CT angiography (CTA) compared with single photon emission CT (SPECT) myocardial perfusion imaging (MPI), which served as the reference standard, for the detection of functionally significant coronary artery disease (CAD). METHODS: 141 consecutive patients (60 ± 10 years, 101 men) were investigated with 64-slice CTA and SPECT MPI; a subset of 35 patients had additional invasive coronary angiography (ICA). The data from CTA and ICA were compared with those from MPI for both cut-offs of ≥ 50% and ≥ 70% stenosis, respectively. RESULTS: The sensitivity, specificity, positive and negative predictive values, and accuracy of CTA, using a cut-off of ≥ 50% for significant stenosis, in detecting inducible perfusion defects on MPI were 96% [95% confidence interval (CI) 88-100%], 61% (95% CI 52-70%), 37% (95% CI 23-49%), 99% (95% CI 97-100%) and 68%, respectively, in patient-based analysis and 97% (95% CI 91-100%), 86% (95% CI 83-89%), 33% (95% CI 24-42%), 100% (95% CI 99-100%) and 87%, respectively, in vessel-based analysis. Applying a cut-off of ≥ 70% for significant stenosis, CTA yielded the following sensitivity, specificity, positive and negative predictive values, and accuracy for the detection of inducible MPI defects: by patient, 65% (95% CI 46-84%), 95% (95% CI 91-99%), 74% (95% CI 50-92%), 92% (95% CI 87-97%) and 89%, respectively; by vessel, 58% (95% CI 42-74%), 97% (95% CI 95-99%), 62% (95% CI 45-79%), 97% (95% CI 95-99%) and 95%, respectively. CONCLUSION: 64-slice CTA is a reliable tool to exclude functionally significant CAD when using a cut-off of ≥ 50% diameter stenosis. By contrast, a cut-off of ≥ 70% diameter narrowing is a strong predictor of ischaemia.