Mark J. Cunningham

Identifying, Characterizing, and Classifying Congenital Anomalies of the Coronary Arteries

The clinical manifestations of coronary artery anomalies vary in severity, with some anomalies causing severe symptoms and cardiovascular sequelae and others being benign. Cardiovascular computed tomography (CT) has emerged as the standard of reference for identification and characterization of coronary artery anomalies. Therefore, it is important for the reader of cardiovascular CT images to be thoroughly familiar with the spectrum of coronary artery anomalies. Hemodynamically significant anomalies include atresia, origin from the pulmonary artery, interarterial course, and congenital fistula. Non-hemodynamically significant anomalies include duplication; high origin; a prepulmonic, transseptal, or retroaortic course; shepherds crook right coronary artery; and systemic termination. In general, coronary arteries with an interarterial course are associated with an increased risk of sudden cardiac death. Coronary artery anomalies that result in shunting, including congenital fistula and origin from the pulmonary artery, are also commonly symptomatic and may cause steal of blood from the myocardium. Radiologists should be familiar with each specific variant and its specific constellation of potential implications.

A hands-off physical therapy assistance robot for cardiac patients

This paper presents a feasibility study of using socially-aware autonomous robots to assist hospitals in reducing the effects of nursing shortages. A hands-off assistive robot is described that provides motivation and support for cardiac patients who must perform regular but painful breathing exercises. Initial validation of the system has garnered positive responses from test subjects and shows that robots have a potential to aid nursing staff in some tasks requiring patient interaction.

Endovascular Management of Mycotic Aortic Aneurysms and Associated Aortoaerodigestive Fistulas

We evaluated the short- and intermediate-term results of endovascular aneurysm repair (EVAR) for mycotic aneurysms. We reviewed all patients undergoing EVAR for mycotic aneurysms at our institution. To be consistent with the existing literature, patients with associated aortoaerodigestive fistulas were included. Aneurysm location, demographics, clinical findings, EVAR success, morbidity, and short- (<30 days) and long-term mortality were reviewed. From 2000 to 2007, 326 patients underwent EVAR. Nine of these (3%) had treatment of a mycotic aneurysm. The average age was 72 years (range 53-86), and seven patients were male. Four of the aneurysms were located in the thoracic aorta, two in the abdominal aorta, and three in the thoracoabdominal aorta. Four patients presented with gastrointestinal bleeding, two with hemoptysis, one with hemothorax, and two with fever. Etiologies included bacteremia from endocarditis and central catheter infection, erosion of anastomotic aneurysms from a previous aortic repair or endograft, erosion of a penetrating ulcer with pseudoaneurysm, infected aortic repair, left chest empyema, and unknown in one patient. Methicillin-resistant Staphylococcus aureus was the only bacteria isolated in 56% of the patients. EVAR successfully excluded the aneurysm or fistula in all nine patients; however, five patients experienced at least one postoperative complication. Two patients expired within 30 days. After 30 days, four additional patients expired; three of these deaths were procedure/aneurysm-related. Of the three survivors, over a mean follow-up of 257 days (range 60-417), one has required excision of an infected endograft with extra-anatomic bypass grafting but is now alive and well. All three surviving patients and two out of four patients expiring after 30 days had received long-term postoperative antibiotics. Despite an in-hospital mortality of 22.2%, EVAR can be used to treat acute complications from mycotic aneurysms and associated aortoaerodigestive fistulas, such as gastrointestinal bleeding, hemoptysis, or hemodynamic instability. As a definitive treatment, EVAR remains suspect and therefore should be considered a bridge to open surgical repair.

Arch and visceral/renal debranching combined with endovascular repair for thoracic and thoracoabdominal aortic aneurysms

OBJECTIVE We report a single-center experience using the hybrid procedure, consisting of open debranching, followed by endovascular aortic repair, for treatment of arch/proximal descending thoracic/thoracoabdominal aortic aneurysms (TAAA). METHODS From 2005 to 2010, 51 patients (33 men; mean age, 70 years) underwent a hybrid procedure for arch/proximal descending thoracic/TAAA. The 30-day and in-hospital morbidity and mortality rates, and late endoleak, graft patency, and survival were analyzed. Graft patency was assessed by computed tomography, angiography, or duplex ultrasound imaging. RESULTS Hybrid procedures were used to treat 27 thoracic (16 arch, 11 proximal descending thoracic) and 24 TAAA (Crawford/Safi types I to III: 3; type IV: 12; type V: 9). The hybrid procedure involved debranching 47 arch vessels or 77 visceral/renal vessels using bypass grafts, followed by endovascular repair. Seventy-five percent of debranching and endovascular repair procedures were staged, with an average interval of 28 days. Major 30-day and in-hospital complications occurred in 39% of patients and included bypass graft occlusion in four, endoleak reintervention in two, and paraplegia in one. Mortality was 3.9%. During a mean follow-up of 13 months, three additional type II endoleaks required intervention, and one bypass graft occluded. No aneurysm rupture occurred during follow-up. Primary bypass graft patency was 95.3%. Actuarial survival was 86% at 1 year and 67% at 3 years. CONCLUSION The hybrid procedure is associated with acceptable rates of mortality and paraplegia when used for treatment of arch/proximal descending thoracic/TAAA. These results support this procedure as a reasonable approach to a difficult surgical problem; however, longer follow-up is required to appraise its ultimate clinical utility.

Ventricular Tachycardia in the Era of Ventricular Assist Devices

Ventricular Tachycardia in the Era of Ventricular Assist Devices.  Sustained ventricular tachycardia (VT) in patients with advanced cardiomyopathy is a potentially life‐threatening arrhythmia. Newer treatment strategies have evolved that combine the use of catheter ablation to target the substrate for VT and ventricular assist devices (VADs) to hemodynamically support the failing ventricle. This editorial is targeted to the practicing clinician caring for these difficult patients. The current article reviews the use of percutaneous VADs to support catheter ablation of VT, the use of durable VADs to support the failing heart in patients with recurrent VT, ventricular arrhythmias in patients with durable VADs, and the use of catheter ablation to treat VT in patients with durable VADs. (J Cardiovasc Electrophysiol, Vol. 22, pp. 359‐363, March 2011)

A comparison of aortic valve replacement via an anterior right minithoracotomy with standard sternotomy: a propensity score analysis of 492 patients

OBJECTIVES Right anterior minithoracotomy with central arterial cannulation is our preferred technique of minimally invasive aortic valve replacement (AVR). We compared perioperative outcomes with this technique to those via sternotomy. METHODS Between March 1999 and December 2013, 492 patients underwent isolated AVR via either sternotomy (SAVR, n = 198) or minimally invasive right anterior thoracotomy (MIAVR, n = 294) in our institution. Univariate comparisons between groups were made to evaluate overall outcomes and adverse events. To control treatment selection bias, propensity scores were constructed from core patient characteristics. A propensity score-stratified analysis of outcome and adverse events was then performed. RESULTS Overall mortality was 2.5 and 1.0% in the SAVR and MIAVR groups, respectively. Hospital and ICU stays were shorter, there was less intraoperative blood product usage, and fewer wound infections in the MIAVR group. There were no differences in other adverse events, including strokes. The composite end-point of alive and adverse event-free was significantly more common in the MIAVR group (83 vs 74%, P = 0.002). After adjusting for the propensity score, hospital and ICU stays remained shorter and intraoperative blood product usage remained less in the MIAVR group. There was no difference in mortality, stroke or other adverse events between groups. CONCLUSION Minimally invasive AVR via an anterior right thoracotomy with predominately central cannulation can be performed with morbidity and mortality similar to that of a sternotomy approach. There appear to be advantages to this minimally invasive approach when compared with sternotomy in terms of less intraoperative blood product usage, lower wound infection rates and decreased hospital stays. If mortality and the occurrence of adverse events are taken together, MIAVR may be associated with better outcomes. As minimally invasive AVR becomes more common, further long-term follow-up is needed and a prospective multicentre randomized trial would be warranted.

Aortic Morphologic Findings After Thoracic Endovascular Aortic Repair for Type B Aortic Dissection

IMPORTANCE Thoracic endovascular aortic repair (TEVAR) is used in the treatment of type B aortic dissections. Information related to aortic morphologic findings and the condition of the abdominal aorta after TEVAR is limited. OBJECTIVE To analyze aortic morphologic findings after TEVAR for type B aortic dissections. DESIGN, SETTING, AND PARTICIPANTS After a retrospective database review, the data for 30 patients who underwent TEVAR from January 1, 2007, through December 31, 2013, for type B aortic dissection were analyzed. Imaging software was used to calculate aortic diameters and volumes of the aorta on computed tomography (CT) or magnetic resonance imaging (MRI). Mean follow-up was 14.4 months. INTERVENTIONS We performed TEVAR to cover proximal thoracic aorta tears in patients who underwent acute or chronic type B aortic dissections. MAIN OUTCOMES AND MEASURES Aortic morphologic findings of pre-TEVAR CT or MRI were compared with the most recent findings of post-TEVAR CT or MRI. Frequency of thoracic false lumen thrombosis (FLT) and false lumen patency (FLP) was determined and the effect on post-TEVAR aortic morphologic findings analyzed. RESULTS Mean (SD) TEVAR increased true lumen diameter (19.50 [6.92] mm to 31.19 [5.36] mm, P < .001) and volume (77.92 [41.70] mL to 166.95 [69.69] mL, P < .001) and decreased false lumen diameter (29.77 [12.55] mm to 21.92 [12.05] mm, P = .001) on post-TEVAR CT or MRI when compared with pre-TEVAR scans. Seventy percent of patients experienced thoracic FLT; 30% had FLP. True lumen volume expansion and false lumen volume regression occurred in patients with FLT (82.07 [46.95] mm to 180.55 [77.99] mm, P < .001 and 161.84 [106.36] mm to 115.76 [140.77] mm, P = .002, respectively) and FLP (68.23 [21.43] mm to 128.22 [21.46] mm, P < .001 and 238.64 [174.00] mm to 198.93 [120.46] mm, P = .04, respectively). Patients with FLT had increased true lumen diameter (15.67 [6.43] mm to 26.13 [7.62] mm, P < .001) and volume (54.86 [30.52] mL to 88.08 [41.07] mL, P = .001) in the abdominal aorta after TEVAR, with no change in total abdominal aortic volume (161.94 [70.12] mL vs 160.36 [82.11] mL, P = .90). Total abdominal aortic volume significantly increased in patients with thoracic FLP (187.24 [89.88] mL to 221.41 [82.64] mL, P = .02). CONCLUSIONS AND RELEVANCE Favorable aortic remodeling of the thoracic aorta occurs after TEVAR for type B aortic dissections in patients with thoracic FLT and FLP. However, failure to achieve thrombosis of the thoracic false lumen negatively influences aortic morphologic findings of the contiguous abdominal aorta.

Anomalous coronary arteries: cardiovascular computed tomographic angiography for surgical decisions and planning.

Cardiovascular computed tomographic angiography (CCTA) provides an understanding of the three-dimensional (3D) coronary artery anatomy in relation to cardiovascular thoracic structures important to the surgical management of anomalous coronary arteries (ACAs). Although some ACA variants are not clinically significant, others can lead to ischemia/infarction, related acute ventricular dysfunction, ventricular arrhythmias, and sudden cardiac death. The CCTA is important to surgical decision making, as it provides noninvasive visualization of the coronary arteries with (1) assessment of origin, course, and termination of coronary artery anomalies in the context of 3D thoracic anatomy, (2) characterization of anatomy helpful for differentiation of benign versus hemodynamically significant variants, (3) identification of other cardiothoracic anomalies, and (4) detection of coronary artery disease. High-risk ACA anatomy in the appropriate clinical setting can require surgical intervention with decisions including minimally invasive versus open sternotomy approach, correction via reimplantation of a coronary artery, alteration of the ACA course without reimplantation, or bypass of an ACA. Given the rarity of ACA, there is limited data in the literature, and significant controversy related to the management issues. The management of ACA requires comprehensive clinical history, thorough assessment of cardiac function, and detailed anatomic imaging. Future studies will need to address the long-term outcome based on detailed assessment of original anatomy and surgical approach.

Contemporary Use of Balloon Aortic Valvuloplasty in the Era of Transcatheter Aortic Valve Implantation

The development of transcatheter aortic valve implantation (TAVI) has increased the use of balloon aortic valvuloplasty (BAV) in treating aortic stenosis. We evaluated our use of BAV in an academic tertiary referral center with a developing TAVI program. We reviewed 69 consecutive stand-alone BAV procedures that were performed in 62 patients (mean age, 77 ± 10 yr; 62% men; baseline mean New York Heart Association functional class, 3 ± 1) from January 2009 through December 2012. Enrollment for the CoreValve(®) clinical trial began in January 2011. We divided the study cohort into 2 distinct periods, defined as pre-TAVI (2009-2010) and TAVI (2011-2012). We reviewed clinical, hemodynamic, and follow-up data, calculating each BAV procedure as a separate case. Stand-alone BAV use increased 145% from the pre-TAVI period to the TAVI period. The mean aortic gradient reduction was 13 ± 10 mmHg. Patients were successfully bridged as intended to cardiac or noncardiac surgery in 100% of instances and to TAVI in 60%. Five patients stabilized with BAV subsequently underwent surgical aortic valve replacement with no operative deaths. The overall in-hospital mortality rate (17.4%) was highest in emergent patients (61%). The implementation of a TAVI program was associated with a significant change in BAV volumes and indications. Balloon aortic valvuloplasty can successfully bridge patients to surgery or TAVI, although least successfully in patients nearer death. As TAVI expands to more centers and higher-risk patient groups, BAV might become integral to collaborative treatment decisions by surgeons and interventional cardiologists.

Thoracic aortic stent-grafting for acute, complicated, type B aortic dissections.

BACKGROUND To report a single-center experience of aortic stent-grafting for the treatment of acute, complicated, type B aortic dissections. METHODS A retrospective review was conducted of the data obtained from all patients who underwent endovascular stent-grafting for acute, type B aortic dissection between 2006 and 2009. The primary and secondary endpoints were 30-day mortality and morbidity rates, respectively. RESULTS In all, 104 thoracic endovascular aortic aneurysm repairs were performed during the study period. Nine (8.6%) patients (six men; mean age: 65 years) underwent thoracic endovascular aortic aneurysm repair for acute, complicated, type B aortic dissections. Seven (78%) patients had uncontrolled hypertension on presentation. Visceral branch vessel involvement of the dissection was limited to the celiac axis origin in one patient with no evidence of visceral malperfusion. The indication for repair was aortic rupture in five patients, renal malperfusion in two, and persistent pain in the remaining two. Average time taken from presentation to surgery was 5.5 days. Two patients presenting with aortic ruptures had retrograde extension of the dissection that required replacement of the aortic valve and ascending aorta. The mean length of thoracic aorta covered was 21 cm. Complete coverage of the left subclavian artery was required in three patients and partial coverage in two. On completion angiogram, two type I endoleaks were detected, one of which was resolved by postoperative day 5. The 30-day mortality rate was 22%. One mortality was secondary to aortic rupture. The other mortality was due to multiorgan system failure. Seven patients (78%) had one or more major complications. There were no strokes or paraplegia. CONCLUSION The association of morbidity and mortality with endovascular stent-grafting for acute, complicated, type B aortic dissections is significant, which most likely reflects the lethal nature of the disease. The precise role of endovascular treatment in these patients remains to be defined.