Campylobacter myocarditis: a rare but potential sequelae of Campylobacter jejuni

Myocarditis is an inflammatory cardiomyopathy with a diverse range of both infective and non-infective causes. It is an important cause of dilated cardiomyopathy worldwide, with a variable clinical course ranging from a mild self-limiting illness to fulminant cardiogenic shock requiring mechanical circulatory support and cardiac transplantation. Here, we describe a case of acute myocarditis secondary to Campylobacter jejuni infection in a man in his 50s who presented with an acute coronary syndrome following a recent gastrointestinal illness.

Adherence to antimicrobial prophylaxis guidelines in cardiac implantable electronic device procedures in two Australian teaching hospitals

Objective This study investigated antibiotic prophylaxis (AP) guideline adherence and the cardiac implantable electronic device (CIED) infection rate in two major Australian public teaching hospitals. Methods In a retrospective observational study, the medical records of patients who underwent CIED procedures between January and December 2017 were reviewed (Hospital A, n = 400 procedures; Hospital B, n = 198 procedures). Adherence to AP guidelines was assessed regarding drug, dose, timing, route and frequency. Infection was identified using follow-up documentation. Results AP was administered in 582 of 598 procedures (97.3%). Full guideline adherence was observed in 33.9% of procedures (203/598) and differed significantly between Hospitals A and B (47.3% vs 7.1%, respectively; P < 0.001). Common reasons for non-adherence were the timing of administration (42.3% vs 60.6% non-adherent in Hospitals A and B, respectively; P < 0.001) and repeat dosing (19.3% vs 78.8% non-adherent in Hospitals A and B, respectively; P < 0.001). Twenty infections were identified over 626.6 patient-years of follow-up (mean (±s.d.) follow-up 1.0 ± 0.3 years). The infection rate was 3.19 per 100 patient-years (P = 0.99 between hospitals). Two devices were removed due to infection; no patients died from CIED infection. Conclusions Although the rate of serious CIED infection was low, there was evidence of highly variable and suboptimal antibiotic use, and potential overuse of AP. What is known about the topic? Previous Australian studies have revealed high rates of inappropriate surgical AP. CIED infections are potentially life threatening, but can be avoided through effective use of AP. However, prolonged durations of AP in this setting may also result in complications, including Clostridioides difficile infection. What does this paper add? This study, the first to our knowledge to focus specifically on adherence to Australian guidelines for AP in CIED procedures, highlighted several common issues between AP in this setting and surgical and procedural AP more broadly. 'Early' and 'late' dose administration and extended post-procedural AP were common. Only 34% of prescriptions fully adhered to the guidelines; practices varied significantly between the two hospitals. What are the implications for practitioners? There is a clear need for institution-specific antimicrobial stewardship strategies to optimise AP in CIED procedures, aligned with the Antimicrobial Stewardship Clinical Care Standard. Patients are being placed at potentially avoidable risk of both complications of extended durations of AP and CIED infection, although the rate of serious CIED infection was low. A standardised approach to surveillance of CIED infections and prospective multisite audits of AP in CIED procedures using a validated tool, such as the Surgical National Antimicrobial Prescribing Survey, are recommended to better inform evidence-based practice. Potential strategies to optimise guideline adherence include prescribing support in patients with immediate penicillin hypersensitivity or methicillin-resistant Staphylococcus aureus colonisation, optimising the in-patient location of drug administration to promote timely dosing, limiting inappropriate post-procedural prophylaxis and routine S. aureus screening and decolonisation.

Noncentrifugal activation patterns in focal RVOT PVC/VT: New insights from high density multielectrode mapping

BACKGROUND

Activation from an automatic focus is thought to show centrifugal spread. In patients with premature ventricular complex/ventricular tachycardia (PVC/VT) from the right ventricular outflow tract (RVOT), the presence of preferential conduction and epicardial connections could however also lead to noncentrifugal wavefront propagation.

OBJECTIVE

To study endocardial activation in RVOT PVC/VT using high-resolution 3D activation mapping.

METHODS

Consecutive patients with frequent idiopathic PVC/VT were studied. High-resolution 3D activation maps were acquired using a multielectrode mapping catheter (Orion, Rhythmia, Boston Scientific). Noncentrifugal activation was defined as a pattern of wavefront propagation which does not show uniform propagation in all directions from one focus. Patients without sustained ablation success and patients with a left-sided PVC origin or with insufficient map density were excluded from the analysis.

RESULTS

Sixteen patients (44% female) with a median age of 54 years (interquartile range [IQR], 47-64) and a median PVC burden of 19% (IQR, 15-27) were studied. High-resolution activation maps consisting of a median number of 1863 mapping points (IQR, 1195-2463 points) demonstrated a centrifugal activation in 6/16 (38%) and a noncentrifugal activation in 10/16 (62%). When comparing patients with centrifugal and noncentrifugal activation, patients with centrifugal activation were older (p = .01), but no differences were found in age, gender, QRS duration of the PVC's and sites of origin in the RVOT. No procedural complications occurred.

CONCLUSIONS

High-resolution multielectrode mapping demonstrates the presence of noncentrifugal activation patterns in some of the patients with idiopathic RVOT PVC/VT. This may indicate the presence of preferential conduction and or epicardial/intramural connections in the outflow tract.

Ischaemic Stroke and the Echocardiographic "Bubble Study": Are We Screening the Right Patients?

BACKGROUND

Patent foramen ovale (PFO) is a potential mechanism for paradoxical embolism in cryptogenic ischaemic stroke or transient ischaemic attack (TIA). PFO is typically demonstrated with agitated saline ("bubble study", BS) during echocardiography. We hypothesised that the BS is frequently requested in patients that have a readily identifiable cause of stroke, that any PFO detected is likely incidental, and its detection often does not alter management.

METHODS

This was a retrospective observational study of patients with recent ischaemic stroke/TIA referred for a BS. Patient demographics, stroke risk factors, vascular/cerebral imaging results and transoesophageal echocardiogram (TOE) reports were recorded. A "modified" Risk of Paradoxical Embolism (RoPE) score was calculated. Change in management was defined as antiplatelet/anticoagulant therapy alteration or referral for PFO closure. Bubble Study complications were recorded.

RESULTS

Among 715 patients with ischaemic stroke/TIA referred for a BS, 8.7% had atrial fibrillation and 9.2% had carotid stenosis ≥70%. At least three stroke risk factors were present in 39.3% and only 47.1% of patients screened had a "modified" RoPE score of >5. A PFO was detected in 248 patients of whom only 31% (77/248) had a subsequent change in management. Of BS performed, 1/924 patients (0.1%) suffered a TIA as a complication.

CONCLUSIONS

The echocardiographic BS is frequently performed in patients that have a readily identifiable cause of stroke and whose PFO unlikely relates to the stroke/TIA. Bubble Study findings resulted in a change in management in the minority. The procedure is safe but the complication rate warrants informed consent.

Lipoprotein(a) and apolipoprotein(a) isoform size: Associations with angiographic extent and severity of coronary artery disease, and carotid artery plaque

BACKGROUND AND AIMS

Lipoprotein(a) [Lp(a)] is an emerging genetic risk factor for cardiovascular disease (CVD). We examined whether plasma Lp(a) concentration and apolipoprotein(a) [apo(a)] isoform size are associated with extent and severity of coronary artery disease (CAD), and the presence of carotid artery plaque.

METHODS

We included in our study male participants (n = 263) from a cohort with angiographically defined premature CAD (Carotid Ultrasound in Patients with Ischemic Heart Disease). The angiographic extent and severity of CAD were determined by the modified Gensini and Coronary Artery Stenosis≥20% (CAGE) scores. Carotid artery plaque was assessed by bilateral carotid B-mode ultrasound. Apo(a) isoform size was determined by LPA Kringle IV-2 copy number (KIV-2 CN).

RESULTS

Lp(a) concentration, but not KIV-2 CN, was positively associated with the Gensini score. The association remained significant following adjustment for conventional CVD risk factors (all p < 0.05). Lp(a) concentration and elevated Lp(a) [≥50 mg/dL] were positively associated with the CAGE≥20 score, independent of conventional CVD risk factors. KIV-2 C N Q1 (lowest KIV-2 CN quartile) was associated with CAGE≥20 score and KIV-2 CN, with the CAGE≥20 score in those without diabetes. In multivariate models that included phenotypic familial hypercholesterolemia or low-density lipoprotein cholesterol, Lp(a) concentration, but not KIV-2 CN, was independently associated with the Gensini and CAGE≥20 scores. No significant associations between Lp(a) concentration and KIV-2 CN with carotid artery plaque were observed.

CONCLUSIONS

Lp(a) concentration, but not apo(a) isoform size, is independently associated with angiographic extent and severity of CAD. Neither Lp(a) nor apo(a) isoform size is associated with carotid artery plaque.

Use of FDG PET scanning to evaluate 5-FU myocardial toxicity as a global metabolic effect rather than vascular spasm

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Background: This is the first ever case series which presents a series of PET images that conclusively demonstrate reversible abnormal myocardial glucose utilisation in 7 patients with normal coronary arteries occurring during 5-FU infusions. Fluoropyrimidine induced myocardial toxicity is estimated to occur in 9% of cases, with some instances proving fatal. Traditionally some hypothesised coronary artery spasm as the mechanism of action behind such events and an animal study suggesting dysfunction of the Krebs cycle, with depletion of high-energy phosphate compounds, was largely ignored. Having observed abnormal myocardial FDG uptake in a patient with chest pain undergoing FDG PET scanning, we prospectively evaluated a further 6 patients presenting with cardiac symptoms whilst receiving infusional 5-FU. Methods: Over an eighteen-month period, 7 patients experienced cardiac like chest pain during 5FU infusion. All were investigated for cardiac ischaemia as per institutional protocol (serial troponin, ECGs and coronary artery imaging), as well as FDG PET scanning to assess FDG uptake in the myocardium. Results: All 7 cases showed reduced FDG uptake throughout the myocardium, with the ventricular blood pool demonstrating a higher affinity for FDG than the myocardium itself. All 7 cases showed normal physiological uptake of FDG in the myocardium on previous and subsequent PET imaging. Imaging of the myocardium and coronary arteries in all cases showed no structural vascular disease. Conclusions: All cases demonstrated a global pattern of reduced FDG myocardial uptake that could not be isolated to a single coronary territory. Angiography or myocardial perfusion scanning demonstrated no significant coronary artery disease, and there were no features consistent with coronary artery spasm found on ECG. This supports the hypothesis that 5FU inhibits physiological myocardial glucose utilisation, thus acting as a direct myocardial toxin. We believe our findings warrant further investigation into the metabolic effects of 5FU on myocardial tissue.

Fluoropyrimidine-associated myocardial toxicity as a global metabolic effect compared to vascular spasm and visibility on FDG PET scanning

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Background: Myocardial toxicity from fluoropyrimidines is a rare but potentially serious side effect, estimated by some as occurring in up to 9%. Coronary spasm has been suggested as the underlying mechanism, despite a lack of supporting evidence and other toxicity mechanisms have been proposed. Matsubara described Krebs cycle dysfunction in the presence of 5FU with depletion of high energy phosphate compounds in rodent myocardial tissue with ECG changes. Following a chance discovery of abnormal myocardial FDG uptake on a PET scan shortly after presenting with presumed 5FU cardiac toxicity (angina, ST elevation, troponin rise; normal coronary vessels on imaging), we prospectively evaluated all instances of angina occurring during 5FU infusion with coronary artery imaging and FDG PET scan. Methods: We identified 5 patients who experienced angina during 5FU therapy. They were investigated for coronary ischaemia and also underwent PET scanning to assess myocardial FDG uptake. Data was collected from patient records, and subsequent cardiac investigations. Results: In all 5 cases, PET scan demonstrated markedly abnormal FDG uptake throughout the myocardium, with the ventricular blood pool demonstrating more FDG activity than myocardium. No significant underlying coronary artery disease was identified. All 5 patients had previous PET scans with normal myocardial FDG uptake. Conclusions: We identified a consistent pattern of abnormal FDG uptake throughout the myocardium for all scanned patients with chest pain following administration of 5FU. This was not restricted to a single arterial territory. There were no typical ECG changes of spasm. Obstructive coronary disease was excluded with angiographic imaging or myocardial perfusion scanning. The FDG PET scans suggest global myocardial metabolic change, supporting the notion of 5FU being a direct myocardial toxin inhibiting myocardial glucose utilization. The myocardium may then be dependent on fatty acid metabolism, posing additional risk to patients on low fat diets. Our data provides new insight into the mechanism of 5-FU myocardial toxicity and further prospective assessment using PET is warranted.

Using quality indicators to compare outcomes of permanent cardiac pacemaker implantation among publicly and privately funded patients

BACKGROUND

Funding source/insurance status has been associated with disparity in the management and outcomes of cardiovascular disease, with poorer outcomes among disadvantaged groups.

AIM

Using proposed quality indicators for permanent pacemaker (PPM) implantation and administrative data, this study aimed to determine whether quality indicator-based outcomes of PPM implantation were comparable for publicly and privately funded patients within Australia's two-tier health system.

METHODS

A population-based cohort study of adults implanted with a PPM between 1995 and 2009 in Western Australia. The association of funding outcomes derived from linked administrative data was tested in multivariate logistic regression models.

RESULTS

There were 9748 PPMs implanted, 48% being among privately funded patients. The mean age was 75 years for both public and private patients. Private patients had better health status (fewer with cardiac conditions and lower non-cardiac comorbidity scores), were less likely to be an emergency admission (33% vs 60%, P < 0.001) and more likely to have dual- or triple-chamber pacing. Mean length of stay was significantly greater for private patients (4.3 (standard deviation 6.3) vs 5.1 (6.8) days <0.001), related to longer elective admissions. Crude mortality was lower for private patients in-hospital (0.7 vs 1.3%), 30-day post-procedure (1.3 vs 2.1%) and at 1 year (7.3 vs 9.5%). Emergency admission, comorbidity and other demographic and clinical factors, not funding source, were significant predictors of these outcomes.

CONCLUSIONS

There was no difference between publicly and privately funded patients in study outcomes, after adjustment for demographic and clinical factors. The exception was longer hospital stay for elective PPM among privately funded patients.

Trends in the incidence and prevalence of cardiac pacemaker insertions in an ageing population

OBJECTIVES

To determine contemporary population estimates of the prevalence of cardiac permanent pacemaker (PPM) insertions.

METHODS

A population-based observational study using linked hospital morbidity and death registry data from Western Australia (WA) to identify all incident cases of PPM insertion for adults aged 18 years or older. Prevalence rates were calculated by age and sex for the years 1995-2009 for the WA population.

RESULTS

There were 9782 PPMs inserted during 1995-2009. Prevalence rose across the study period, exceeding 1 in 50 among people aged 75 or older from 2005. This was underpinned by incidence rates which rose with age, being highest in those 85 years or older; over 500/100 000 for men throughout, and over 200/100 000 for women. Rates for patients over 75 were more than double the rates for those aged 65-74 years. Women were around 40% of cases overall. The use of dual-chamber and triple-chamber pacing increased across the study period. A cardiac resynchronisation defibrillator was implanted for 58% of patients treated with cardiac resynchronisation therapy.

CONCLUSIONS

Rates of insertion and prevalence of PPM continue to rise with the ageing population in WA. As equilibrium has probably not been reached, the demand for pacing services in similarly well-developed economies is likely to continue to grow.

Implantable cardiac defibrillators and end-of-life care--time for reflection, deliberation and debate?

Heart failure (HF) is a common condition associated with high rates of morbidity and mortality. Implantable cardiac defibrillators (ICDs) are an important management strategy in HF management and decrease mortality for both primary and secondary prevention. An emerging body of literature identifies the challenges of managing ICDs at the end of life. This report discusses a critical incident experienced by a HF team in a referral centre and outlines the issues to be considered in advancing discussion and debate of managing ICDs at the end of life. Engaging in debate, discussion and consensus guidelines is likely to be crucial in minimising distress and burden for clinicians, patients and their families alike.

Hypersensitive carotid sinus syndrome due to neurofibromatosis-1 and manifested by repeated episodes of syncope

A 28-year-old patient with neurofibromatosis-1 presented with syncope. The exam demonstrated a mass adjacent and inferior to the right occiput that extended to the posterior lateral right-sided neck. Initial invasive and noninvasive testing was negative. Imaging of her head and neck demonstrated a large neurofibroma enveloping her right carotid sinus without vessel occlusion or evidence of malignancy. An event recorder documented asystole. A pacemaker was implanted to avoid the surgical morbidity of removing the neck mass. The patient has since been free of syncope. We believe neurofibromatosis-1 should be included in the differential of syncope.