Safety of short-term dual antiplatelet therapy after drug-eluting stents:An updated meta-analysis with direct and adjusted indirect comparison of randomized control trials

Background: Duration of dual antiplatelet therapy (DAPT) following drug-eluting stents (DES) remains controversial and is a topic of ongoing research. Methods: Direct and adjusted indirect comparisons of all the recent randomized control trials (RCTs) were performed to evaluate the safety of short-term versus long-term DAPT following DES. Results: 8 RCTs were identified and 7 (16,318 subjects) were included. 4 groups of 3 vs 12 months, 6 vs 12 months, 6 vs 24 months and 12 vs 24 months of DAPT were used for direct comparison. There was no significant difference in stent thrombosis, myocardial infarction (MI), stroke and revascularization, cardiovascular and all-cause mortality between the different durations in all 4 groups. Pooling trials of 3–6 months of DAPT against 12 months, we found a significant reduction in the risk of total bleeding (RR 0.61, 95% CI 0.43–0.87). Adjusted indirect comparison between 3 vs 6 months, 3 vs 24 months and 6 vs 24 month duration of DAPT showed no significant differences in risk of death or MI, or revascularization between 3 or 6 months and 24 months. However, 24 months of DAPT was associated with significantly more bleeding than 3 or 6 months. Conclusions: 3 to 6 months of DAPT following second generation DES and above is safe with no increased risk of thrombotic complications and mortality, and lower bleeding risk. However a tailored approach may be more appropriate for high-risk patients. Keywords: Percutaneous coronary intervention; Drug-eluting stent; Acute coronary syndrome; Dual antiplatelet treatment; Duration of therap

Breaking an image encryption algorithm based on chaos

Recently, a chaos-based image encryption algorithm called MCKBA (Modified Chaotic-Key Based Algorithm) was proposed. This paper analyzes the security of MCKBA and finds that it can be broken with a differential attack, which requires only four chosen plain-images. Performance of the attack is verified by experimental results. In addition, some defects of MCKBA, including insensitivity with respect to changes of plain-image/secret key, are reported.Comment: 10 pages, 4 figure

Breaking a Chaotic Cryptographic Scheme Based on Composition Maps

Recently, a chaotic cryptographic scheme based on composition maps was proposed. This paper studies the security of the scheme and reports the following findings: 1) the scheme can be broken by a differential attack with $6+\lceil\log_L(MN)\rceil$ chosen-plaintext, where $MN$ is the size of plaintext and $L$ is the number of different elements in plain-text; 2) the scheme is not sensitive to the changes of plaintext; 3) the two composition maps do not work well as a secure and efficient random number source.Comment: 9 pages, 7 figure