Characteristics of COVID-19 Patients Who Progress to Pneumonia on Follow-Up Chest Radiograph: 236 Patients from a Single Isolated Cohort in Daegu, South Korea

Objective@#We investigated the prevalence of pneumonia in novel coronavirus disease 2019 (COVID-19) patients using chest radiographs to identify the characteristics of those with initially negative chest radiographs, who were positive for pneumonia on follow-up. @*Materials and Methods@#Retrospective cohort data of 236 COVID-19 patients were reviewed. Chest radiography was performed on admission, with serial radiographs obtained until discharge. The ‘positive conversion group’ was defined as patients whose initial chest radiographs were negative but were positive for pneumonia during follow-up. Patients with initially positive chest radiographs were defined as the ‘initial pneumonia group.’ Patients with negative initial and follow-up chest radiographs were defined as the ‘non-pneumonia group.’ Clinical and laboratory findings were compared between groups, and predictors of positive conversion were investigated. @*Results@#Among 236 patients, 108 (45.8%) were in the non-pneumonia group, 69 (29.2%) were in the initial pneumonia group, and 59 (25%) were in the positive conversion group. The patients in the ‘initial pneumonia group’ and ‘positive conversion group’ were older, had higher C-reactive protein (CRP) and lactate dehydrogenase levels, and lower absolute lymphocyte counts than those in the ‘non-pneumonia group’ (all p 0.5 mg/dL (OR: 3.91, 95% CI: 1.54–9.91, p = 0.004) were independent predictors for future development of pneumonia. @*Conclusion@#More than a half of COVID-19 patients initially had normal chest radiographs; however, elderly patients (≥ 45 years of age) with abnormal laboratory findings (elevated CRP and low absolute lymphocyte counts) developed pneumonia on follow-up radiographs.

Accuracy of implantable loop recorders for detecting atrial tachyarrhythmias after atrial fibrillation catheter ablation

Background@#Implantable loop recorders (ILRs) can provide an enhanced possibility to detect atrial fibrillation (AF), but the accuracy, especially the positive predictive value (PPV), is controversial. This study aimed to evaluate the accuracy of ILRs for detecting AF through a comparison with Holter. @*Method and results@#Thirteen patients who underwent AF ablation were enrolled. ILRs were implanted in all patients, who were scheduled to have Holter monitorings after the procedure. The incidence of AF was compared between the two modalities and analyzed for any correlations. A total of 51 Holters (67,985.5 min) and concomitant ILRs were available for the comparison. The judgment of the presence of AF did not perfectly correlate between the ILR and Holter (Kappa = 0.866, P < 0.001). In the ILR data, the sensitivity of detecting AF on the Holter was 81.6% (95% confidence interval [CI] 0.812–0.820; P < 0.001). The specificity was 99.9% (95% CI 0.998–0.999; P < 0.001). When the ILR detected AF, the PPV was 99.5% (95% CI 0.994–0.995), but the ILR did not detect AF, and the negative predictive value was 94.2% (95% CI 0.941–0.944). A separate analysis of AF/atrial tachycardia (AT) showed that the AT detection rate of the ILR was 2.3%. @*Conclusion@#The ILR had a low false positive value and high PPV for AF events. However, it was limited in identifying AT.

Effect of carvedilol on premature ventricular complexes originating from the ventricular outflow tract

Background@#Carvedilol is one of the most effective beta-blockers in reducing ventricular tachyarrhythmias and mortality in patients with heart failure. One of the possible antiarrhythmic mechanisms of carvedilol is the suppression of store overload-induced Ca2+ release, especially for the triggered activity. @*Objectives@#Premature ventricular complex (PVC) originating from the ventricular outflow tract (OT) is the most common form of idiopathic PVC, and its main mechanism is related to triggered activity. We evaluate the efficacy of carvedilol to suppress the OT PVC. @*Methods@#The electronic medical records at our hospital were screened to identify OT PVC patients treated with carvedilol. Clinical, electrocardiographic, and Holter monitoring studies were reviewed. @*Results@#A total of 25 patients who underwent Holter monitoring before and after carvedilol administration were found and enrolled. The mean age of the patients was 54.9 ± 13.9 years, and the mean dose of carvedilol was 18.2 ± 10.2 mg (sustained release formulation, 8/16/32 mg). The 24-h burden of PVC in 18 (72%) of 25 patients was significantly reduced from 12.2 ± 9.7% to 4.4 ± 6.7% (P = 0.006). In seven patients, the burden of PVC was changed from 7.1 ± 6.1% to 9.8 ± 8.4% (P = 0.061). There was no difference in age, carvedilol dose, duration of treatment, ventricular function, and left atrial size between responding and non-responding groups. @*Conclusion@#In this retrospective pilot study, treatment with carvedilol showed PVC suppression in 72% of patients. Now, we are conducting a prospective, randomized, multicenter study to evaluate the effect of carvedilol on OT PVC (Clinical trial registration: FOREVER trial, Clinical-Trials.gov: NCT03587558).

Optical Coherence Tomography: Defined Plaque Erosion after Removal of a Coronary Guidewire

No abstract available.

Long-term outcomes of intravascular ultrasound-guided implantation of bare metal stents versus drug-eluting stents in primary percutaneous coronary intervention

BACKGROUND/AIMS: While drug-eluting stents (DESs) have shown favorable outcomes in ST-segment elevation myocardial infarction (STEMI) compared to bare metal stents (BMSs), there are concerns about the risk of stent thrombosis (ST) with DESs. Because intravascular ultrasound (IVUS) guidance may help optimize stent placement and improve outcomes in percutaneous coronary intervention (PCI) patients, we evaluated the impact of IVUS-guided BMS versus DES implantation on long-term outcomes in primary PCI. METHODS: In all, 239 STEMI patients received DES (n = 172) or BMS (n = 67) under IVUS guidance in primary PCI. The 3-year incidence of major adverse cardiac events (MACEs) including death, myocardial infarction (MI), target vessel revascularization (TVR), and ST was evaluated. RESULTS: There was no difference in all cause mortality or MI. However, the incidence of TVR was 23.9% with BMS versus 9.3% with DES (p = 0.005). Thus, the number of MACEs was significantly lower with DES (11.0% vs. 29.9%; p = 0.001). The incidence of definite or probable ST was not different (1.5% vs. 2.3%; p = 1.0). IVUS-guided DES implantation (hazard ratio [HR], 0.25; 95% confidence interval [CI], 0.08 to 0.78; p = 0.017), stent length (HR, 1.03; 95% CI, 1.00 to 1.06; p = 0.046), and multivessel disease (HR, 3.01; 95% CI, 1.11 to 8.15; p = 0.030) were independent predictors of MACE. CONCLUSIONS: In patients treated with primary PCI under IVUS guidance, the use of DES reduced the incidence of 3-year TVR versus BMS. However, all cause mortality and MI were similar between the groups. The incidence of ST was low in both groups.

Spontaneous coronary artery dissection diagnosed by intravascular ultrasound and followed up by cardiac computed tomography

No abstract available.

The Efficacy of the Cystatin C Based Glomerular Filtration Rate in the Estimation of Safe Contrast Media Volume

BACKGROUND AND OBJECTIVES: The risk of contrast-induced nephropathy (CIN) is significantly influenced by baseline renal function and the amount of contrast media (CM). We evaluated the usefulness of the cystatin C (CyC) based estimated glomerular filtration rate (eGFR(CyC)) in the prediction of CIN and to determine the safe CM dosage. SUBJECTS AND METHODS: We prospectively enrolled a total of 723 patients who received percutaneous coronary intervention (PCI) and investigated the clinical factors associated with the development of CIN. Renal function was calculated as eGFR(CyC) and a modified diet in the renal disease (MDRD) equation, respectively. Systemic exposure of CM was calculated as CM volume to eGFR ratio. We conducted a regression analysis to evaluate the predictive role of CM volume to eGFR(CyC) for the risk of CIN. RESULTS: The incidence of CIN was 4.0% (29/723). The patients with CIN had a lower hemoglobin level, decreased renal function, and a higher CyC value, and had greater CM exposure. Through multivariate regression analyses, hemoglobin {odds ratio (OR) 0.743, p=0.032}, CM volume/eGFR(CyC) (OR 1.697, p=0.006) and CM volume/MDRD (OR 2.275, p<0.001) were found to be independent predictors for CIN. In the receiver operating characteristic curve analysis, fair discrimination for CIN was found at a CM volume/eGFR(CyC) level of 4.493 (C-statics=0.814), and at this value, the sensitivity and specificity were 79.3% and 80.0%, respectively. CONCLUSION: Both the CM volume/MDRD and CM volume/eGFR(CyC) method would be simple, useful indicators for determining the safe CM-dose based on eGFR value before PCI. However, there was no significantly different predictive value between creatinine and CyC based GFR estimations.

Acute Stent Thrombosis and Heparin Induced Thrombocytopenia in a Patient With ST-Segment Elevation Myocardial Infarction

Heparin is an essential drug in the treatment of acute coronary syndrome and it is used during percutaneous coronary intervention (PCI). Heparin-induced thrombocytopenia (HIT), albeit a serious complication of heparin therapy characterized by thrombocytopenia and high risk for venous and arterial thrombosis, has rarely been previously reported during PCI. We report a case of an acute stent thrombosis due to an unusual cause, HIT during primary PCI, in a patient with acute myocardial infarction.