PubMed · 15407769
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
H SIEDEK. 1949-11-11. [Angina pectoris].. https://pubmed.ncbi.nlm.nih.gov/15407769/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
PURPOSE: The aim of this study was to evaluate spiral multidetector computed tomography (MDCT) angiography using 64-slice technique in the detection of functionally relevant coronary artery stenoses (CAS). METHODS: Thirty-eight patients (62+/-11 years, 28 men) with stable angina (26 with suspected and 12 with known coronary artery disease) were investigated using 64-slice MDCT angiography and gated myocardial perfusion SPECT (gated SPECT); a subgroup of 30 patients had additional invasive coronary angiography (ICA). Stenoses with luminal narrowing of >or=50% were defined as "significant" in MDCT angiography and ICA. MDCT angiography was compared with gated SPECT and the combination of gated SPECT plus ICA with respect to the detection of functionally relevant CAS. RESULTS: The sensitivity, specificity and negative and positive predictive values of MDCT angiography in detecting reversible perfusion defects on gated SPECT were 63%, 80%, 94% and 32%, respectively, in vessel-based analysis and 71%, 62%, 72% and 60%, respectively, in patient-based analysis. If only reversible perfusion defects on gated SPECT with CAS >or=50% on ICA were considered, the sensitivity, specificity and negative and positive predictive values were, respectively, 85%, 79%, 98% and 33% for vessel-based analysis and 85%, 59%, 83% and 61% for patient-based analysis. CONCLUSION: Sixty-four slice MDCT angiography failed to predict the functional relevance of CAS, but had a high negative predictive value in the exclusion of functionally relevant CAS in symptomatic patients.
Explore the source record for details and available documents.
In this article, we present a frailty model using the generalized gamma distribution as the frailty distribution. It is a power generalization of the popular gamma frailty model. It also includes other frailty models such as the lognormal and Weibull frailty models as special cases. The flexibility of this frailty distribution makes it possible to detect a complex frailty distribution structure which may otherwise be missed. Due to the intractable integrals in the likelihood function and its derivatives, we propose to approximate the integrals either by Monte Carlo simulation or by a quadrature method and then determine the maximum likelihood estimates of the parameters in the model. We explore the properties of the proposed frailty model and the computation method through a simulation study. The study shows that the proposed model can potentially reduce errors in the estimation, and that it provides a viable alternative for correlated data. The merits of proposed model are demonstrated in analysing the effects of sublingual nitroglycerin and oral isosorbide dinitrate on angina pectoris of coronary heart disease patients based on the data set in Danahy et al. (sustained hemodynamic and antianginal effect of high dose oral isosorbide dinitrate. Circulation 1977; 55:381-387).