Zakaria Almuwaqqat

The association between acute mental stress and abnormal left atrial electrophysiology

Acute stress may trigger atrial fibrillation (AF), but the underlying mechanisms are unclear. We examined if acute mental stress results in abnormal left atrial electrophysiology as detected by more negative deflection of P‐wave terminal force in lead V1 (PTFV1), a well‐known marker of AF risk.

Myocardial Ischemia and Mobilization of Circulating Progenitor Cells

Background The response of progenitor cells (PCs) to transient myocardial ischemia in patients with coronary artery disease remains unknown. We aimed to investigate the PC response to exercise‐induced myocardial ischemia (ExMI) and compare it to flow mismatch during pharmacological stress testing. Methods and Results A total of 356 patients with stable coronary artery disease underwent 99mTc‐sestamibi myocardial perfusion imaging during exercise (69%) or pharmacological stress (31%). CD34+ and CD34+/chemokine (C‐X‐C motif) receptor 4 PCs were enumerated by flow cytometry. Change in PC count was compared between patients with and without myocardial ischemia using linear regression models. Vascular endothelial growth factor and stromal‐derived factor‐1α were quantified. Mean age was 63±9 years; 76% were men. The incidence of ExMI was 31% and 41% during exercise and pharmacological stress testing, respectively. Patients with ExMI had a significant decrease in CD34+/chemokine (C‐X‐C motif) receptor 4 (−18%, P=0.01) after stress that was inversely correlated with the magnitude of ischemia (r=−0.19, P=0.003). In contrast, patients without ExMI had an increase in CD34+/chemokine (C‐X‐C motif) receptor 4 (14.7%, P=0.02), and those undergoing pharmacological stress had no change. Plasma vascular endothelial growth factor levels increased (15%, P<0.001) in all patients undergoing exercise stress testing regardless of ischemia. However, the change in stromal‐derived factor‐1α level correlated inversely with the change in PC counts in those with ExMI (P=0.03), suggesting a greater decrease in PCs in those with a greater change in stromal‐derived factor‐1α level with exercise. Conclusions ExMI is associated with a significant decrease in circulating levels of CD34+/chemokine (C‐X‐C motif) receptor 4 PCs, likely attributable, at least in part, to stromal‐derived factor‐1α–mediated homing of PCs to the ischemic myocardium. The physiologic consequences of this uptake of PCs and their therapeutic implications need further investigation.

Performance of J-CTO and PROGRESS CTO Scores in Predicting Angiographic Success and Long-term Outcomes of Percutaneous Coronary Interventions for Chronic Total Occlusions

Patient selection for and predicting clinical outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) remain challenging. We hypothesized that both J-CTO (Multicenter Chronic Total Occlusion Registry of Japan) and PROGRESS CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) scores will predict not only angiographic success but also long-term clinical outcomes of the patients who underwent PCI of CTO. Of 325 CTO PCIs performed at 2 Emory University hospitals from January 2012 to August 2015, 249 patients with complete baseline clinical, angiographic and follow-up data, were included in this analysis. Major adverse cardiovascular events (MACEs) consisted of a composite of death, myocardial infarction, and target vessel revascularization. Mean age was 63 ± 11 years old and mean follow-up was 19.8 ± 13.1 months. Angiographic success rates increased from 74.5% in 2012 to 85.7% in 2015. Greater J-CTO and PROGRESS CTO scores were not only associated with lower likelihood of angiographic success but also higher rates of long-term MACE. Compared with the scores of 0 to 2, J-CTO and PROGRESS CTO scores of ≥3 were associated with higher MACE. Multivariable analysis demonstrated that PROGRESS CTO scores of ≥3, male sex, and peripheral vascular disease were independent predictors of MACE. In conclusion, J-CTO and PROGRESS CTO scores are useful in predicting procedural success. In addition, the PROGRESS CTO score, and to a lesser degree J-CTO score, have predictive value for long-term outcomes in patients who underwent CTO PCI.

A New Algorithm for Predicting the Progression from Paroxysmal to Persistent Atrial Fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmias which affects more than 2 million US adults. Paroxysmal AF is characterized by recurrent AF episodes that stop on their own in less than 7 days. If the AF episodes last for more than 7 days, it is unlikely that they will stop on their own, and they are then known as persistent AF episodes which necessitate treatment with pharmacological or electrical cardioversion. This paper develops a new algorithm for predicting the progression from paroxysmal to persistent AF. In particular, the proposed model classifies cardiac waveforms for subjects who developed persistent AF episodes in a much shorter time from others who needed a longer time to develop them. The proposed model can be further personalized to assist clinicians by identifying patients that are at high risk of developing persistent AF episodes in order to deliver proactive treatment therapies that can prevent worsening their physiological state.

Sensitive Troponin I and Stress Testing in the Emergency Department for the Early Management of Chest Pain Using 2-Hour Protocol

Background: Despite improvements in identifying high-risk patients with non-ST segment ACS (acute coronary syndrome), low risk patients presenting with atypical chest pain and non-diagnostic Electrocardiogram (ECG) continued to undergo unnecessary admissions and testing. Since 1992, our chest pain protocol included using 4-hour serial biomarkers from ED admission in combination with stress testing to evaluate these patients. Our study aimed at determining whether a new accelerated diagnostic protocol using sensitive cardiac troponin I (cTnI) 2 hours after admission to the ED followed by stress testing is safe and effective in emergency settings, allowing for appropriate triage, earlier discharge and reducing costs. Methods: We conducted a single center randomized trial at Presence St. Francis Hospital Chest pain center in Evanston, Illinois enrolling sixty-four consecutive patients with atypical chest pain and non-diagnostic ECG, participants were randomized to accelerated 2 hrs protocol or our pre-existing 4-hrs protocol. Sixty patients completed the protocol and were randomized to either a 2-hour (29 patients) or 4-hour protocol using both I-STAT and PATHFAST cTnI (31 Patients). Troponin I was evaluated at 0 and at 2 hours from ED presentation with and additional draw for patients in the 4-hour rule out-group. Patients with normal serial biomarkers were then evaluated with stress testing and qualified for earlier discharge if the stress test was negative, while those with a positive biomarker at any time were admitted. Thirty-six patients had exercise treadmill stress test and 24 patients had either nuclear or Echo stress test. Results: Fifty-three patients had a normal stress test and were discharged home. One patient in the 4-hour group with normal serial troponins developed ventricular tachycardia/fibrillation during the recovery period of a regular stress test. Six patients had a positive PATHFAST cTnI and a normal I-STAT cTnI at 2-hours. Two out of these six patients evaluated by coronary angiography. One patient had severe tortuous coronaries but no significant obstructive lesion and one had a severe CAD who needed Coronary artery bypass grafting (CABG). Three of the six patients had a normal stress test and one patient decided to leave without further testing. None of the patients with a normal stress test had a major cardiac event or adverse cardiac outcome at six-month follow up. Conclusion: This study demonstrates that the 2 hours accelerated protocol using high sensitivity Troponin assay at 0 and 2 hours with comprehensive clinical evaluation and ECG followed by stress testing might be successful in identifying low-risk patient population who may benefit from early discharge from ED reducing associated costs and length of stay.

Statins in Cardio-Oncology

Statins are among the most widely prescribed pharmacological agents. Since first described in 1978 as hydroxy-3-methylglutaryl-coenzyme A (HMG–CoA) reductase competitive inhibitor agents, statins have been the subject of extensive preclinical, animal, and clinical studies. Their utility and pleiotropic effects extend beyond lipid lowering effects in patients with hypercholesterolemia and atherosclerotic cardiovascular disease (ASCVD). Statins may be useful in cancer patients who may have traditional cardiovascular risk factors such as hyperlipidemia or have established ASCVD. Recently their use in oncology population has gained significant attention as a tumor suppressor agent or adjunct to chemotherapy. Some observational studies have suggested that statins may reduce cancer-related mortality and may have some protective effect from chemotherapy- and radiotherapy-induced cardiovascular toxicity. However, randomized controlled trials are needed to inform guidelines for using statins in oncology population for preventive and therapeutic goals.

EVALUATION OF CHEST PAIN IN THE EMERGENCY ROOM USING A 2 HOUR SENSITIVE TROPONIN I (CTNI)

Many chest pain patients are admitted to the hospital annually without coronary artery disease. In 1992, we randomized patients to direct admission versus a 4-hour serial cardiac marker protocol that led to the development of the 4-hour rule-out protocol. Our study demonstrated that patients could