Applications of Machine Learning in Cardiology.

In this digital era, artificial intelligence (AI) is establishing a strong foothold in commercial industry and the field of technology. These effects are trickling into the healthcare industry, especially in the clinical arena of cardiology. Machine learning (ML) algorithms are making substantial progress in various subspecialties of cardiology. This will have a positive impact on patient care and move the field towards precision medicine. In this review article, we explore the progress of ML in cardiovascular imaging, electrophysiology, heart failure, and interventional cardiology.

Artificial intelligence and machine learning in cardiovascular computed tomography.

Computed tomography (CT) is emerging as a prominent diagnostic modality in the field of cardiovascular imaging. Artificial intelligence (AI) is making significant strides in the field of information technology, the commercial industry, and health care. Machine learning (ML), a branch of AI, can optimize the performance of CT and augment the assessment of coronary artery disease. These ML platforms can automate multiple tasks, perform calculations, and integrate information from a variety of data sources. In this review article, we explore the ML in CT imaging.

Antiplatelet and anticoagulation therapy during percutaneous coronary interventions: A review for the interventionalist.

Pharmacotherapy for percutaneous coronary interventions is essential to optimize the balance between thrombosis and bleeding. Currently, choices abound for the selection of antiplatelet and anticoagulation therapies during percutaneous intervention (PCI). This review article discusses the mechanisms, pharmacokinetics/dynamics, and clinical data behind the various pharmacotherapies including; aspirin, thienopyridines, glycoprotein IIb/IIIa inhibitors, vorapaxar, heparin, direct thrombin inhibitors, and factor Xa inhibitors.

Valve in valve transcatheter aortic valve implantation (ViV-TAVI) versus redo-Surgical aortic valve replacement (redo-SAVR): A systematic review and meta-analysis.

BACKGROUND: Bioprosthetic (BP) valves have been increasingly used for aortic valve replacement over the last decade. Due to their limited durability, patients presenting with failed BP valves are rising. Valve in Valve - Transcatheter Aortic Valve Implantation (ViV-TAVI) emerged as an alternative to the gold standard redo-Surgical Aortic Valve Replacement (redo-SAVR). However, the utility of ViV-TAVI is poorly understood. METHODS: A systematic electronic search of the scientific literature was done in PubMed, EMBASE, SCOPUS, Google Scholar, and ClinicalTrials.gov. Only studies which compared the safety and efficacy of ViV-TAVI and redo-SAVR head to head in failed BP valves were included. RESULTS: Six observational studies were eligible and included 594 patients, of whom 255 underwent ViV- TAVI and 339 underwent redo-SAVR. There was no significant difference between ViV-TAVI and redo- SAVR for procedural, 30 day and 1 year mortality rates. ViV-TAVI was associated with lower risk of permanent pacemaker implantation (PPI) (OR: 0.43, CI: 0.21-0.89; P = 0.02) and a trend toward increased risk of paravalvular leak (PVL) (OR: 5.45, CI: 0.94-31.58; P = 0.06). There was no significant difference for stroke, major bleeding, vascular complications and postprocedural aortic valvular gradients more than 20 mm-hg. CONCLUSION: Our results reiterate the safety and feasibility of ViV-TAVI for failed aortic BP valves in patients deemed to be at high risk for surgery. VIV-TAVI was associated with lower risk of permanent pacemaker implantation with a trend toward increased risk of paravalvular leak.

Utilization of the Impella for hemodynamic support during percutaneous intervention and cardiogenic shock: an insight.

INTRODUCTION: Impella is a catheter-based micro-axial flow pump placed across the aortic valve, and it is currently the only percutaneous left ventricular assist device approved for high-risk percutaneous coronary intervention and cardiogenic shock. Areas Covered: Even though several studies have repeatedly demonstrated the excellent hemodynamic profile of Impella in high-risk settings, it remains underutilized. Here we aim to provide an up-to-date summary of the available literature on Impellas use in High risk settings as well as the practical aspects of its usage. Expert Commentary: Percutaneous coronary interventions in high rsk settings have always been challenging for a physician. Impella 2.5 and CP, have been proven safe, cost effective and feasible in High Risk Percutaneous coronary Interventions with an excellent hemodynamic profile.

Long-term Outcome after Percutaneous Coronary Intervention Compared with Minimally Invasive Coronary Artery Bypass Surgery in the Elderly.

BACKGROUND: Elderly patients with unstable coronary artery disease (CAD) have better outcomes with coronary revascularization than conservative treatment. With the improvement in percutaneous coronary intervention (PCI) techniques using drug eluting-stents, this became an attractive option in elderly. Minimally invasive coronary artery bypass grafting (MICS-CABG) is a safe and effective alternative to conventional CABG. We aimed to explore the long-term outcomes after PCI vs MICS-CABG in ≥75 year-old patients with severe CAD. METHODS: A total of 1454 elderly patients (≥75 year-old patients) underwent coronary artery revascularization between January 2005 and December 2009. Patients were selected in the study if they have one of the Class-I indications for CABG. Groups were divided according to the type of procedure, PCI or MICS-CABG, and 5 year follow-up. RESULTS: Among 175 elderly patients, 109 underwent PCI and 66 had MICS-CABG. There was no significant difference observed in both groups with long-term all-cause mortality (31 PCI vs 21% MICS-CABG, p=0.151) and the overall 5 year survival was similar on Kaplan-Meier curve (Log rank p=0.318). The average length of stay in hospital was significantly shorter in the PCI than in the MICS-CABG group (4.3 vs 7.8 days, p<0.001). Only 4.7% of the PCI group were discharged to rehabilitation facility compared with 43.9% of the MICS-CABG group (p<0.001). The rate of repeat revascularization was significantly higher in the PCI group than in the MICS-CABG group (15 vs 3%, p=0.014). CONCLUSION: Among elderly patients, long-term all-cause mortality is similar after PCI and MICS-CABG. However, there is a significantly higher rate of repeat revascularization after PCI.

Biodegradable polymer stents vs second generation drug eluting stents: A meta-analysis and systematic review of randomized controlled trials.

AIM: To evaluate the premise, that biodegradable polymer drug eluting stents (BD-DES) could improve clinical outcomes compared to second generation permanent polymer drug eluting stents (PP-DES), we pooled the data from all the available randomized control trials (RCT) comparing the clinical performance of both these stents. METHODS: A systematic literature search of PubMed, Cochrane, Google scholar databases, EMBASE, MEDLINE and SCOPUS was performed during time period of January 2001 to April 2015 for RCT and comparing safety and efficacy of BD-DES vs second generation PP-DES. The primary outcomes of interest were definite stent thrombosis, target lesion revascularization, myocardial infarction, cardiac deaths and total deaths during the study period. RESULTS: A total of 11 RCT's with a total of 12644 patients were included in the meta-analysis, with 6598 patients in BD-DES vs 6046 patients in second generation PP-DES. The mean follow up period was 16 mo. Pooled analysis showed non-inferiority of BD-DES, comparing events of stent thrombosis (OR = 1.42, 95%CI: 0.79-2.52, P = 0.24), target lesion revascularization (OR = 0.99, 95%CI: 0.84-1.17, P = 0.92), myocardial infarction (OR = 1.06, 95%CI: 0.86-1.29, P = 0.92), cardiac deaths (OR = 1.07, 95%CI 0.82-1.41, P = 0.94) and total deaths (OR = 0.96, 95%CI: 0.80-1.17, P = 0.71). CONCLUSION: BD-DES, when compared to second generation PP-DES, showed no significant advantage and the outcomes were comparable between both the groups.

Gender, Racial, and Health Insurance Differences in the Trend of Implantable Cardioverter-Defibrillator (ICD) Utilization: A United States Experience Over the Last Decade.

Prior studies have highlighted disparities in cardiac lifesaving procedure utilization, particularly among women and in minorities. Although there has been a significant increase in implantable cardioverter-defibrillator (ICD) insertion, socioeconomic disparities still exist in the trend of ICD utilization. With the use of the Nationwide Inpatient Sample from 2003 through 2011, we identified subjects with ICD insertion (procedure code 37.94) and cardiac resynchronization defibrillator (procedure code 00.50, 00.51) as codified by the International Classification of Diseases, Ninth Revision, Clinical Modification. Overall, 1 020 076 ICDs were implanted in the United States from 2003 to 2011. We observed an initial increase in ICD utilization by 51%, from 95 062 in 2003 to 143 262 in 2006, followed by a more recent decline. The majority of ICDs were implanted in men age ≥65 years. Implantation of ICDs was 2.5× more common in men than in women (402 per million vs 163 per million). Approximately 95% of the ICDs were implanted in insured patients, and 5% were used in the uninsured population. There has been a significant increase in ICD implantation in blacks, from 162 per million in 2003 to 291 per million in 2011. We found a significant difference in the volume of ICD implants between the insured and the uninsured patient populations. Racial disparities have narrowed significantly in comparison with those noted in earlier studies and are now more reflective of the population demographics at large. On the other hand, significant gender disparities continue to exist.

Prognostic impact of atrial fibrillation on clinical outcomes of acute coronary syndromes, heart failure and chronic kidney disease.

Atrial fibrillation (AF) is the most common type of sustained arrhythmia, which is now on course to reach epidemic proportions in the elderly population. AF is a commonly encountered comorbidity in patients with cardiac and major non-cardiac diseases. Morbidity and mortality associated with AF makes it a major healthcare burden. The objective of our article is to determine the prognostic impact of AF on acute coronary syndromes, heart failure and chronic kidney disease. Multiple studies have been conducted to determine if AF has an independent role in the overall mortality of such patients. Our review suggests that AF has an independent adverse prognostic impact on the clinical outcomes of acute coronary syndromes, heart failure and chronic kidney disease.

Trends in hospitalization for atrial fibrillation: epidemiology, cost, and implications for the future.

Atrial fibrillation (AF) is the most prevalent arrhythmia worldwide and the most common arrhythmia leading to hospitalization. Due to a substantial increase in incidence and prevalence of AF over the past few decades, it attributes to an extensive economic and public health burden. The increasing number of hospitalizations, aging population, anticoagulation management, and increasing trend for disposition to a skilled facility are drivers of the increasing cost associated with AF. There has been significant progress in AF management with the release of new oral anticoagulants, use of left atrial catheter ablation, and novel techniques for left atrial appendage closure. In this article, we aim to review the trends in epidemiology, hospitalization, and cost of AF along with its future implications on public health.

9.1 cm abdominal aortic aneurysm in a 69-year-old male patient.

We are presenting a case of one of the largest un-ruptured abdominal aortic aneurysm ever reported. Presented here is a rare case of a 69-year-old active smoker male with history of hypertension and incidental diagnosis of abdominal aortic aneurysm of 6.2 cm in 2003, who refused surgical intervention at the time of diagnosis with continued smoking habit and was managed medically. Patient was subsequently admitted in 2012 to the hospital due to unresponsiveness secondary to hypoglycemia along with diagnosis of massive symptomatic pulmonary embolism and non-ST elevation myocardial infarction. With the further inpatient workup along with known history of abdominal aortic aneurysm, subsequent computed tomography scan of abdomen pelvis revealed increased in size of infrarenal abdominal aortic aneurysm to 9.1 cm of without any signs of rupture. Patient was unable to undergo any surgical intervention this time because of his medical instability and was eventually passed away under hospice care.

Major complications of cryoballoon catheter ablation for atrial fibrillation and their management.

Atrial fibrillation (AF) is the most common symptomatic and sustained cardiac arrhythmia. It affects approximately 2-3 million people in the USA alone with an increased incidence and prevalence worldwide. It is associated, in addition to worsening quality of life, with increased morbidity and mortality especially in poorly controlled AF, affecting mostly those older than 65 years of age. Radiofrequency ablation was found to be a good strategy for focal isolation of pulmonary veins triggering from the vulnerable atrial substrate but is a time-consuming procedure and carries the risk of multiple complications like tamponade which could be fatal, atrioesophageal fistula and local thrombus formation at the site of ablation. Cryoballoon ablation with pulmonary vein isolation has emerged in the past few years as a breakthrough novel technology for the treatment of drug-refractory AF. It is a relatively simple alternative for point-by-point radiofrequency ablation of paroxysmal AF and is associated with fewer incidences of fatal complications such as cardiac perforation. As experience with this new tool accumulates, the field faces new challenges in the form of rare compilations including gastroparesis, phrenic nerve palsy, atrioesophageal fistula, pulmonary vein stenosis, thromboembolism pericardial effusion, and tamponade.

Rare case of coronary to pulmonary vein fistula with coronary steal phenomenon.

Coronary artery fistulas are abnormal connections between coronary artery territories and cardiac chambers or major vessels, most of them are congenital. Patients with coronary artery fistula can be asymptomatic or present with different symptoms like angina. Cardiac computed tomography (CT) is one of the best modalities for diagnosis. We present an elderly patient that presented with angina symptoms, non invasive stress test was positive for ischemic heart disease, coronary angiogram could not reveal any obstructive lesions, but an abnormal branch of the left descending coronary artery (LAD), cardiac CT showed fistula that connect left anterior descending coronary artery to left superior pulmonary vein. Our case is extremely rare as most of the reported cases were fistulas between LAD and pulmonary artery, but in our case the fistula between LAD and left superior pulmonary vein. In addition, our patients' symptoms resolved with anti-ischemic medical treatment without any surgical intervention.

Cardiac resynchronization therapy in acute pulmonary edema: A case report.

We are reporting a case of 71-year old lady with a dual chamber demand pacemaker, who developed acute pulmonary edema due to an acute left ventricular (LV) dysfunction and worsening in mitral valve regurgitation after atrioventricular nodal ablation for uncontrolled atrial fibrillation. This was attributed to right ventricular apical pacing leading to LV dyssynchronization. Patient dramatically improved within 12-24 h after upgrading her single chamber pacemaker to biventricular pacing. Our case demonstrates that biventricular pacing can be an effective modality of treatment of acute congestive heart failure. In particular, it can be used when it is secondary to LV dysfunction and severe mitral regurgitation attributed to significant dyssynchrony created by right ventricular pacing in patients with atrioventricular nodal ablation for chronic atrial fibrillation.

Use of continuous venovenous hemofiltration for acute renal failure due to multiple myeloma cast nephropathy.

Renal insufficiency is associated with high morbidity and mortality in multiple myeloma. One of the common causes for acute renal failure in multiple myeloma is cast nephropathy. It is important to reduce the levels of light chains to improve renal failure and also the overall outcome. Plasmapheresis has failed to show any significant improvement in renal failure due to cast nephropathy as demonstrated in a recent randomized control trial. Here, we present a case series of three patients who were treated with continuous venovenous hemofiltration as a modality to remove these free light chains. There was improvement in renal failure in these patients with decrease in the levels of free light chains. These patients remained off hemodialysis on follow-up and two of them were able to undergo hematopoietic stem cell transplantation.