Bad company? The pericardium microbiome in people investigated for tuberculosis pericarditis in an HIV-prevalent setting.

Background: The microbiome likely plays a role in tuberculosis (TB) pathogenesis. We evaluated the site-of-disease microbiome and predicted metagenome in people with presumptive tuberculous pericarditis, a major cause of mortality, and explored for the first time, the interaction between its association with C-reactive protein (CRP), a potential diagnostic biomarker and the site-of-disease microbiome in extrapulmonary TB. Methods: People with effusions requiring diagnostic pericardiocentesis (n=139) provided background sampling controls and pericardial fluid (PF) for 16S rRNA gene sequencing analysed using QIIME2 and PICRUSt2. Blood was collected to measure CRP. Results: PF from people with definite (dTB, n=91), probable (pTB, n=25), and non- (nTB, n=23) tuberculous pericarditis differed in ß-diversity. dTBs were, vs. nTBs, Mycobacterium-, Lacticigenium-, and Kocuria- enriched. Within dTBs, HIV-positives were Mycobacterium-, Bifidobacterium- , Methylobacterium- , and Leptothrix -enriched vs. HIV-negatives and HIV-positive dTBs on ART were Mycobacterium - and Bifidobacterium -depleted vs. those not on ART. Compared to nTBs, dTBs exhibited short-chain fatty acid (SCFA) and mycobacterial metabolism microbial pathway enrichment. People with additional non-pericardial involvement had differentially PF taxa (e.g., Mycobacterium -enrichment and Streptococcus -depletion associated with pulmonary infiltrates). Mycobacterium reads were in 34% (31/91), 8% (2/25) and 17% (4/23) of dTBs, pTBs, and nTBs, respectively. ß-diversity differed between patients with CRP above vs. below the median value ( Pseudomonas -depleted). There was no correlation between enriched taxa in dTBs and CRP. Conclusions: PF is compositionally distinct based on TB status, HIV (and ART) status and dTBs are enriched in SCFA-associated taxa. The clinical significance of these findings, including mycobacterial reads in nTBs and pTBs, requires evaluation.

Comparing the findings and diagnostic sensitivity of cardiovascular magnetic resonance in biopsy confirmed acute myocarditis with infarct-like vs. heart failure presentation.

BACKGROUND: Cardiovascular magnetic resonance (CMR) is considered the reference imaging modality in providing a non-invasive diagnosis of acute myocarditis (AM), as it allows for the detection of myocardial injury associated with AM. However, the diagnostic sensitivity and pattern of CMR findings appear to differ according to clinical presentation. METHODS: This is a retrospective cross-sectional study. Consecutive adult patients presenting to a single tertiary centre in South Africa between August 2017 and January 2022 with AM confirmed on endomyocardial biopsy (EMB) were enrolled. Patients with infarct-like symptoms, defined as those presenting primarily with chest pain syndrome with associated ST-T wave changes on electrocardiogram, or heart failure (HF) symptoms, defined as clinical signs and symptoms of HF without significant chest discomfort, were compared using contrasted CMR and parametric techniques with EMB confirmation of AM as diagnostic gold standard. RESULTS: Forty-one patients were identified including 23 (56%) with infarct-like symptoms and 18 (44%) with HF symptoms. On CMR, the infarct-like group had significantly higher ejection fractions of both ventricles (LVEF 55.3 ± 15.3% vs. 34.4 ± 13.5%, p < 0.001; RVEF 57.3 ± 10.9% vs. 42.9 ± 18.2%, p = 0.008), without significant differences in end diastolic volumes (LVEDVI 82.7 ± 30.3 ml/m2 vs. 103.4 ± 35.9 ml/m2, p = 0.06; RVEDVI 73.7 ± 22.1 ml/m2 vs. 83.9 ± 29.9 ml/m2, p = 0.25). Myocardial oedema was detected more frequently on T2-weighted imaging (91.3% vs. 61.1%, p = 0.03) and in more myocardial segments [3.0 (IQR 2.0-4.0) vs. 1.0 (IQR 0-1.0), p = 0.003] in the infarct-like group. Despite the absence of a significant statistical difference in the prevalence of late gadolinium enhancement (LGE) between the two groups (95.7% vs. 72.2%, p = 0.07), the infarct-like group had LGE detectable in significantly more ventricular segments [4.5 (IQR 2.3-6.0) vs. 2.0 (IQR 0-3.3), p = 0.02] and in a different distribution. The sensitivity of the original Lake Louise Criteria (LLC) was 91.3% in infarct-like patients and 55.6% in HF patients. When the updated LLC, which included the use of parametric myocardial mapping techniques, were applied, the sensitivity improved to 95.7% and 72.2% respectively. CONCLUSION: The pattern of CMR findings and its diagnostic sensitivity appears to differ in AM patients presenting with infarct-like and HF symptoms. Although the sensitivity of the LLC improved with the addition of parametric mapping in the HF group, it remained lower than that of the infarct-like group, and suggests that EMB should be considered earlier in the course of patients with clinically suspected AM presenting with HF.

Subacute dual stent thromboses in a COVID-19-positive patient.

The hypercoagulable state of COVID-19 is resulting in an increasing number of unexpected venous and arterial thromboses in patients. We report a case of subacute dual coronary stent thrombosis in the setting of COVID-19 and we provide a brief review of current management recommendations.

Prevalence of cardiotropic viruses in adults with clinically suspected myocarditis in South Africa.

OBJECTIVES: To determine the prevalence and types of viral pathogens in the myocardium of patients presenting with clinically suspected myocarditis in South Africa. METHOD: This is a prospective cross-sectional study. Consecutive adults presenting to a single tertiary centre in South Africa between August 2017 and January 2021 who fulfilled the European Society of Cardiology's diagnostic criteria for clinically suspected myocarditis and who had undergone the appropriate investigations, including cardiac MRI (CMR) and endomyocardial biopsy (EMB), were included. RESULTS: One hundred and two patients with clinically suspected myocarditis were enrolled. Acute myocarditis (AM) was confirmed by CMR or EMB in 82 (80.39%) patients. Viral genomes were detected by PCR in EMB specimens of 50 patients with AM. Parvovirus B19 (PVB19) was the most frequently detected virus, in 37 as monoinfection and 4 as coinfection. This was followed by Epstein-Barr virus (n=6), human herpesvirus 6 (n=2) and human bocavirus (n=1). PVB19 was also detected in 9 patients with no evidence of AM on CMR or EMB. CONCLUSION: Viral myocarditis is the most common form of myocarditis in South Africa. Local viral prevalence appears to be similar those of the developed world. The clinical significance and pathogenic role of PVB19 remains questioned, and its local background prevalence will have to be further investigated.

Routine use of fluoroscopic and real-time transthoracic echocardiographic guidance to ensure safety of right ventricular endomyocardial biopsy in a low-volume center.

To determine whether the routine use of real-time transthoracic echocardiographic (TTE) guidance in addition to fluoroscopy would ensure the safety of right ventricular endomyocardial biopsy (RV EMB) in a low-volume center. RV EMB is a valuable tool and plays an important role in the diagnosis and management of patients with myocardial diseases. However, it has yet to gain widespread acceptance due to its perceived low diagnostic yield and concerns regarding its invasive nature and potential complications. Although the safety of EMB when performed by experienced operators in high-volume centers is well established, the complication rate in low-volume centers is less well defined but appears to be higher. This is a retrospective single-center cross-sectional study. Consecutive adult patients who underwent RV EMB procedures at Tygerberg Hospital (Cape Town, South Africa) between August 2017 and December 2020 were included. RV EMB was successfully performed in 85 patients. No major complications were reported. Five (5.88%) patients experienced minor complications: three transient right bundle branch blocks and two hemodynamically stable ventricular tachycardia. A definitive biopsy diagnosis was made in 37 (43.54%) patients. The average procedural time was 27.06 min, which equated to 4.09 min per specimen taken. The routine use of real-time TTE guidance in addition to fluoroscopy ensured the safety of RV EMB in a low-volume center without unnecessarily prolonging procedural time.

Radial artery dilatation to improve access and lower complications during coronary angiography: the RADIAL trial.

AIMS: The aim of this study was to explore the use of prolonged occlusion flow-mediated dilatation (PO-FMD) to dilate the radial artery prior to cannulation to increase cannulation success, reduce puncture attempts and reduce access-site complications in transradial coronary angiography. METHODS AND RESULTS: A total of 1,156 patients undergoing transradial coronary angiography were randomised into PO-FMD and sham PO-FMD groups. PO-FMD was achieved by a 10-minute inflation of a blood pressure cuff on the arm to above systolic pressure, followed by deflation with resultant radial artery dilation. In the sham PO-FMD group the cuff was not inflated. Operators were blinded to the intervention. Five hundred and eighty (580) patients were randomised to the sham PO-FMD group and 576 to the PO-FMD group. Cannulation failure was reduced with PO-FMD, with cannulation failure rates of 2.7% in the PO-FMD group and 5.8% in the sham PO-FMD group (p=0.01).The number of puncture attempts was reduced with the use of PO-FMD, with a median of one attempt in the PO-FMD group and two in the sham PO-FMD group (p<0.001). Radial artery pulsation loss (RAPL) was reduced with PO-FMD, with 1.4% in the PO-FMD group and 3.8% in the sham PO-FMD group (p=0.02). CONCLUSIONS: PO-FMD reduces cannulation failure rates, decreases puncture attempts, and decreases RAPL during transradial coronary angiography.

Inferior ST-elevation myocardial infarction managed with a pharmacoinvasive strategy and conservative management of delayed atrioventricular block: classical case report.

BACKGROUND: The 2017 ESC guideline on patients with ST-segment elevation myocardial infarction (STEMI) provides guidance regarding the optimal management of these patients. Transient atrioventricular (AV) block is a relatively common complication of inferior STEMI and its management is also addressed in the guidelines. CASE SUMMARY: A 64-year-old gentleman with multiple cardiovascular risk factors presented to the emergency department with a history of ischaemic type chest pain and evidence of inferior ST-segment elevation on his electrocardiogram (ECG). First-degree AV block was noted on his initial ECG. He was given thrombolytic therapy as part of a pharmacoinvasive strategy of reperfusion. He, however, failed fibrinolytic therapy, and emergency angiography revealed critical disease of the right coronary artery which was successfully stented. Subsequent to reperfusion, he developed complete AV block without evidence of re-infarction, which was managed conservatively with successful resolution of the block after 7 days of expectant management with temporary transvenous pacing. DISCUSSION: We highlight some of the important management principles from the ESC guideline of STEMI including timing and the management of AV block in these patients. In addition, we highlight the role of a pharmacoinvasive strategy for reperfusion where timeous primary percutaneous coronary intervention cannot be performed. The usefulness of such a strategy within the COVID-19 era is also emphasized.