Effectiveness of Messenger RNA Coronavirus Disease 2019 Vaccines Against Symptomatic Severe Acute Respiratory Syndrome Coronavirus 2 Infections During the Delta Variant Epidemic in Japan: Vaccine Effectiveness Real-time Surveillance for SARS-CoV-2 (VERSUS).

BACKGROUND: Although high vaccine effectiveness of messenger RNA (mRNA) coronavirus disease 2019 (COVID-19) vaccines has been reported in studies in several countries, data are limited from Asian countries, especially against the Delta (B.1.617.2) variant. METHODS: We conducted a multicenter test-negative case-control study in patients aged ≥16 years visiting hospitals or clinics with signs or symptoms consistent with COVID-19 from 1 July to 30 September 2021, when the Delta variant was dominant (≥90% of SARS-CoV-2 infections) nationwide in Japan. Vaccine effectiveness of BNT162b2 or mRNA-1273 against symptomatic SARS-CoV-2 infections was evaluated. Waning immunity among patients aged 16-64 years was also assessed. RESULTS: We enrolled 1936 patients, including 396 test-positive cases and 1540 test-negative controls for SARS-CoV-2. The median age was 49 years, 53.4% were male, and 34.0% had underlying medical conditions. Full vaccination (receiving 2 doses ≥14 days before symptom onset) was received by 6.6% of cases and 38.8% of controls. Vaccine effectiveness of full vaccination against symptomatic SARS-CoV-2 infections was 88.7% (95% confidence interval [CI], 78.8%-93.9%) among patients aged 16-64 years and 90.3% (95% CI, 73.6%-96.4%) among patients aged ≥65 years. Among patients aged 16-64 years, vaccine effectiveness was 91.8% (95% CI, 80.3%-96.6%) within 1-3 months after full vaccination, and 86.4% (95% CI, 56.9%-95.7%) within 4-6 months. CONCLUSIONS: mRNA COVID-19 vaccines had high effectiveness against symptomatic SARS-CoV-2 infections in Japan during July-September 2021, when the Delta variant was dominant nationwide.

Optimal lipid-lowering therapy in patients who were functionally deferred percutaneous coronary intervention.

Deferral of percutaneous coronary intervention (PCI) for functionally insignificant stenosis, defined as fractional flow reserve (FFR) > 0.80, is associated with favorable long-term prognoses. The lower-the-better strategy for low-density lipoprotein cholesterol (LDL-C) management is an established non-angioplasty therapy to improve the clinical outcomes of patients undergoing PCI. We examined the optimal LDL-C management in cases of intermediate coronary stenosis with deferred PCI on the basis of FFR values. This observational study included 273 consecutive patients with a single target vessel and deferred PCI with an FFR > 0.80. Patients with an FFR of 0.81-0.85 (n = 93) and those with FFR > 0.85 (n = 180) were classified into the lower (< 100 mg/dL) and higher (≥ 100 mg/dL) LDL-C groups. The endpoint was major adverse cardiovascular and cerebrovascular events (MACCE), including death, non-fatal myocardial infarction, ischemic stroke, heart failure hospitalization, and unplanned revascularization. Patients with an FFR of 0.81-0.85 had a significantly higher MACCE rate than those with an FFR > 0.85 (log-rank, p = 0.003). In patients with an FFR of 0.81-0.85, the lower LDL-C group showed a significantly lower MACCE rate than the higher LDL-C group (log-rank, p = 0.006). However, the event rate did not differ significantly between the two groups in patients with FFR > 0.85 (log-rank, p = 0.84). Uncontrolled LDL-C levels were associated with higher MACCE rates in cases with deferred PCI due to an FFR of 0.81-0.85. This high-risk population for adverse cardiovascular events should receive strict LDL-C-lowering therapy.

Direct Oral Anticoagulants Affect Activated Clotting Time During and Bleeding Events After Percutaneous Coronary Intervention.

Inappropriately high activated clotting time (ACT) during percutaneous coronary intervention (PCI) is associated with an increased risk of bleeding events. However, whether the prescription of direct oral anticoagulants (DOACs) affects ACT kinetics during heparin use and adverse clinical events in patients who underwent PCI remains unclear. We aimed to evaluate the relations between ACT changes during and adverse clinical events after PCI in patients who were prescribed DOAC. This observational study included 246 patients who underwent PCI at the 2 cardiovascular centers who were not receiving warfarin and whose ACT was recorded immediately before and 30 minutes after injection of unfractionated heparin. Patients were divided into 2 groups according to DOAC prescription at the time of the index PCI: DOAC users (n = 31) and nonusers (n = 215). Any bleeding and systemic thromboembolic events were investigated until 30 days after PCI. The average age of this population was 70.5 years, and 66.3% were male. Average ACT was significantly higher in DOAC users than nonusers both before and 30 minutes after unfractionated heparin induction (157.2 ± 30.1 vs 131.8 ± 25.1 seconds, p <0.001; 371.1 ± 122.2 vs 308.3 ± 82.2 seconds, p <0.001; respectively). The incidence of systemic thromboembolism after PCI was low and comparable between the 2 groups (0% vs 3.7%, p = 0.60). However, the rate of any bleeding event was significantly higher in DOAC users than in nonusers (16.1% vs 4.7%, p = 0.028). Patients receiving DOAC have higher ACT during PCI and higher incidence of bleeding events than those not receiving DOAC.