The Burden of Unnecessary Testing From a Regularly Ordered Laboratory Assay: Age-Adjusted d-Dimer Quality Improvement Study.

Diagnosing acute pulmonary embolism (PE) involves clinical suspicion in combination with sequential diagnostic tests including d-dimer laboratory assays. Although the sensitivity of this assay is well validated and thoroughly tested, a false-positive result can lead to unnecessary and costly testing. The age-adjusted d-dimer (AADD) has been suggested in the literature to improve the usefulness of d-dimer cutoffs and safely decrease iodine and radiation exposure associated with definitively ruling out PE with computed tomographic angiography (CTA).1 We present an internal retrospective review utilizing the novel AADD cutoff to rule out PE and evaluate the potential extent of unnecessary testing with CTA. Using the AADD cutoff would have led to a 21.2% reduction in computerized tomography pulmonary embolus protocol. This internal quality improvement study suggests that changing our institutional conventional d-dimer to the novel AADD would provide a superior quality and cost-benefit.

Dermatologic Conundrum: A Cardiac Condition Masqueraded as a Dermatologic Distraction.

A 38-year-old male presented to the emergency department (ED) complaining of extreme pain and a petechial rash on the left ankle for two weeks associated with generalized fatigue, intermittent fevers, and weight loss. He was discharged home from the ED on pain medications. He returned a few days later with a progressive rash that involved the entire left lower extremity to the level of the knee. He was diagnosed with herpes zoster (shingles) and was prescribed acyclovir and steroids. After several days, the patient presented for the third time to the ED. He developed a right lower extremity discomfort this time. The pain in bilateral lower extremities had become unbearable. His cardiac examination revealed a systolic murmur at the apex and a faint diastolic murmur at the left sternal border. Ultimately, he had an echocardiogram that demonstrated both a bicuspid aortic valve and large vegetation on the anterior leaflet of the mitral valve, and his blood culture grew Streptococcus mitis and Streptococcus oralis. The patient was subsequently diagnosed with subacute bacterial endocarditis thought to be sourced from his poor dentition. The diagnosis of infective endocarditis is often delayed due to its nonspecific clinical presentations. Our case displays an unusual skin manifestation of IE that may be present in the absence of other signs and symptoms of the disease.

False activation of the cardiac catheterization laboratory: The price to pay for shorter treatment delay.

INTRODUCTION: In patients with acute ST elevation myocardial ischemia (STEMI), national efforts have focused on reducing door-to-balloon (D2B) times for primary percutaneous coronary intervention (PCI). This emphasis on time-to-treatment may increase the rate of inappropriate cardiac catheterization laboratory (CCL) activations and unnecessary healthcare utilization. To achieve lower D2B times, community hospitals and EMS systems have enabled emergency medical technicians (EMTs) and emergency department (ED) physicians to activate the CCLs without immediately consulting a cardiologist. OBJECTIVE: The purpose of this study is to determine the rate and main causes of inappropriate activation of the CCL which will aid in finding solutions to reduce this occurrence. METHOD: This is a retrospective study, based on an electronic medical system review of all inappropriate CCL activation who presented to Providence Hospital and Medical Centers (PHMC) in Michigan, from January 2015 to July 2016. RESULTS: The CCL was activated 375 times for suspected STEMI. The false STEMI activation was identified in 47 patients which represents 12.5% of total CCL activation. The vast majority of this false activation was due to non-diagnostic electrocardiogram (ECG) that did not meet the STEMI criteria. CONCLUSION: The subjective interpretation of the ECG by EMTs and ED physicians tend to show a wide variability, which may lead to higher-than-anticipated false activation rates of up to 36% in one study. Some studies had reported that up to 72% of inappropriate activations were caused by ECG misinterpretations. These false activations have ramifications that lead to both clinical and financial costs.

Differential effect of regadenoson versus dipyridamole on heart rate in patients with left bundle branch block: How does it affect the results of pharmacological nuclear stress testing?

BACKGROUND: Myocardial perfusion imaging (MPI) stress test is performed either using exercise as a stress modality or through the use of pharmacological vasodilator agents in those who cannot exercise. Regadenoson and dipyridamole are some of the most common vasodilator agents used. We aim to study the effect of these agents on the heart rate and the imaging results. METHODS: This was a retrospective study which included 187 patients with left bundle branch block. Patients received either dipyridamole or regadenoson during the myocardial perfusion imaging stress test. Charts were reviewed, and patient characteristics were recorded, as well as baseline heart rate, peak heart rate during stress, and angiographic data if available. RESULTS: Regadenoson increased peak, absolute and relative heart rates significantly more compared to dipyridamole. The peak heart rate for Regadenoson was 94.1 ± 17.36 and for dipyridamole it was 85.38 ± 16.48 BPM (P < 0.001). The relative and absolute heart rate increase in the regadenoson group were 40.75 ± 23.01% and 26.06 ± 13.44 BPM, respectively. The relative and absolute heart rate increase in the dipyridamole group were 24.61 ± 18.25% and 16.23 ± 10.97 BPM. The frequency of reversible septal defects was similar in both groups (54% for Regadenoson vs. 63% for Dipyridamole; P = 0.24). CONCLUSIONS: There is a statistically significant increase in heart rate with the use of regadenoson for MPI compared to dipyridamole. However, the number of septal perfusion defects was similar between the two groups. The effect of this increase in heart rate, while statistically significant, is likely of no clinical significance.

Transcervical Carotid Artery Stenting Without Flow Reversal: A Report of Two Cases.

BACKGROUND The use of a carotid artery stent (CAS) is a management option for high-risk patients with carotid artery stenosis. An access site for CAS that involves the transcervical approach may be performed percutaneously or may require a cutdown, and usually includes a flow-reversal system to reduce the risk of embolization. Two cases are presented where the transcervical approach to CAS incorporated a distal filter for embolic protection, with a successful outcome. CASE REPORT 1. A 78-year-old man with a history of prior irradiation for head and neck cancer presented for CAS after clinical evaluation showed that he was a poor candidate for carotid endarterectomy (CEA). A femoral approach for carotid artery access was not successful due to a tortuous type III aortic arch. A surgical cutdown of the carotid artery was performed with the use of a distal filter, and the CAS was inserted with no embolic events. 2. A 69-year-old man with an anatomically high bifurcation of his carotid artery was not a candidate for CEA due to limited carotid artery access. Diagnostic carotid angiography was also difficult to perform. The CAS was successfully sited with the use of a distal filter and with no post-procedural complications. CONCLUSIONS CAS is an option for carotid artery stenosis in patients with high surgical risk for CEA. Although a flow-reversal system is usually used to reduce embolic events, these two cases demonstrate that one can also avoid embolism with a distal filter instead.

Real-world use of PCSK9 inhibitors: A single-center experience.

OBJECTIVE: Hyperlipidemia is an important risk factor for atherosclerotic cardiovascular disease. Many patients are intolerant to or have limited benefit from statins. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have been approved for treating hyperlipidemia in these patients. We sought to investigate the impact of these medications in a real-world cardiology practice. METHODS: This was a retrospective study of 17 patients with either heterozygous familial hypercholesterolemia or established atherosclerotic cardiovascular disease with low-density lipoprotein cholesterol (LDL-C) levels above the treatment target despite maximally tolerated statins. Baseline lipid profile was compared with a repeat lipid profile obtained 4 to 6 weeks after initiating treatment with a PCSK9 inhibitor. RESULTS: The average duration of PCSK9 inhibitor treatment was 10.7 months. Lipid profile comparison showed that total cholesterol decreased from 243 ± 72 to 148 ± 39 (mg/dL) (39% reduction), triglycerides decreased from 185 ± 86 to 149 ± 62 (mg/dL) (19.5% reduction), high-density lipoprotein cholesterol increased from 56 ± 20 to 62 ± 26 (mg/dL) (10.7% increase), and LDL-C decreased from 154 ± 30 to 57 ± 32 (mg/dL) (63% reduction) from baseline. CONCLUSIONS: PCSK9 inhibitors as add-on therapy to maximally tolerated statins resulted in an approximately 63% reduction in LDL-C.

Arteriolar vs. valvular thrombosis: Pick your evil!

BACKGROUND: Anticoagulation therapy for mechanical prosthetic valves is limited to vitamin K antagonists, unfractionated heparin and low-molecular-weight-heparin. Other forms of anticoagulation are either contraindicated or have not been well studied. Hence, anticoagulation for preexisting mechanical valves is controversial if vitamin K antagonists are contraindicated. We present a case involving an end-stage-renal disease patient with both mitral and aortic mechanical valves who developed warfarin-induced calciphylaxis. CASE PRESENTATION: A 72-year-old male with history of end-stage renal disease, chronic atrial fibrillation and rheumatic heart disease status post mitral and aortic valve replacements presented with complaints of left thigh erythema with skin induration. Despite multiple antibiotic regimens for presumed cellulitis, the skin lesions progressed to necrotic ulcers. A biopsy revealed evidence of calciphylaxis; a lethal condition typically associated with renal disease. The patient was on warfarin for anticoagulation of his mechanical heart valves as well as prophylactically for atrial fibrillation. Warfarin contributes to the development of calciphylaxis and needed to be exchanged to avoid progression of the ulceration. The only other acceptable option for long-term anticoagulation was subcutaneous unfractionated heparin but this approach was not taken. The patient suffered from further sequelae of calciphylaxis and eventually expired. CONCLUSION: Calciphylaxis is a rare, serious disorder that presents with skin ischemia and necrosis mainly in end-stage renal disease patients. The pathogenesis and treatment are poorly understood and the prognosis remains grave. It is proposed that certain medications, including warfarin, contribute to its evolution. The optimal anticoagulation therapy in those with concomitant warfarin-induced calciphylaxis and mechanical valves is undetermined. Further studies are essential to establish new anticoagulation regimens in these devastating circumstances.

Rapid resolution of left ventricular thrombus with apixaban therapy.

It is a common medical practice to anticoagulate an asymptomatic left ventricular mural thrombus following an ST-elevation myocardial infarction using a vitamin K antagonist. Novel oral anticoagulants have not been studied extensively in this context, and therefore, no recommendations have been made for their use. A 67-year-old male physician with no significant medical history presented to the cardiology clinic complaining of shortness of breath that had been gradually worsening over a 2-week period and was found to have an anterior wall myocardial infarction with apical left ventricular thrombus that was treated with apixaban. We present a case of rapid resolution of left ventricular thrombus with the use of apixaban for anticoagulation. Although there are no guideline recommendations for this use, there have been case series and case reports that have shown safety and efficacy. Apixaban can be used for rapid resolution of left ventricular thrombus treatment.

Off label use of direct oral anticoagulants for left ventricular thrombus. Is it appropriate?

A 57 year old gentleman with a history of non-ischemic cardiomyopathy and paroxysmal atrial fibrillation presented with worsening lower extremity edema and dyspnea on exertion. He had been compliant with his medications including rivaroxaban (Xarelto) for atrial fibrillation that he takes with the evening meal daily. His echocardiogram showed an ejection fraction of 10-15% and a new left ventricle (LV) apical thrombus. During his hospital stay, he developed right sided weakness. Magnetic Resonance Imaging showed a subacute infarct involving the left parietal lobe. The decision was made to discontinue rivaroxaban and initiate heparin infusion instead. Meanwhile, the patient's neurological symptoms were closely monitored. The patient was then transitioned to warfarin. He was eventually transferred to the rehabilitation floor with minimal residual neurologic weakness. Left ventricular thrombus is an important complication in the setting of systolic dysfunction. The combination of blood stasis, endothelial injury and hypercoagulability, is a prerequisite for in-vivo thrombus formation. The slow onset of action and reversal, need for frequent monitoring, narrow therapeutic range, dietary restrictions, and multiple drug interactions limit the use of vitamin K antagonists. Direct-acting oral anticoagulants (DOACs) do not have these limitations and may also reduce the risk of hemorrhagic stroke. Our patient developed an LV thrombus while on uninterrupted DOAC therapy.