Splenic switch-off in regadenoson 82Rb-PET myocardial perfusion imaging: assessment of clinical utility

BACKGROUND

Splenic switch-off (SSO) is a phenomenon describing a decrease in splenic radiotracer uptake after vasodilatory stress. We aimed to assess the diagnostic utility of regadenoson-induced SSO.

METHODS

We included consecutive patients who had clinically indicated Regadenoson Rb-82 PET-MPI for suspected CAD. This derivation cohort (no perfusion defects and myocardial flow reserves (MFR) ≥ 2) was used to calculate the splenic response ratio (SRR). The validation cohort was defined as patients who underwent both PET-MPI studies and invasive coronary angiography (ICA).

RESULTS

The derivation cohort (n = 100, 57.4 ± 11.6 years, 77% female) showed a decrease in splenic uptake from rest to stress (79.9 ± 16.8 kBq⋅mL vs 69.1 ± 16.2 kBq⋅mL, P < .001). From the validation cohort (n = 315, 66.3 ± 10.4 years, 67% male), 28% (via SRR = 0.88) and 15% (visually) were classified as splenic non-responders. MFR was lower in non-responders (SRR; 1.55 ± 0.65 vs 1.76 ± 0.78, P = .02 and visually; 1.18 ± 0.33 vs 1.79 ± 0.77, P < .001). Based on ICA, non-responders were more likely to note obstructive epicardial disease with normal PET scans especially in patients with MFR < 1.5 (SRR; 61% vs 34% P = .05 and visually; 68% vs 33%, P = .01).

CONCLUSION

Lack of splenic response based on visual or quantitative assessment of SSO may be used to identify an inadequate vasodilatory response.

Type A Aortic Dissection with Antegrade Intimointimal Intussusception

We describe a 60-year-old man with a history of hypertension who presented to an outside emergency department with chest pain and left lower extremity numbness and weakness. Computed tomography (CT) revealed Stanford type A aortic dissection (TAAD), and he was transferred to our institution for emergent open surgical repair. Review of the outside CT showed no dissection flap in the ascending aorta and a complex flap in the proximal descending thoracic aorta consistent with complex intimal transection at the sinotubular junction and intimointimal intussusception. This case presents high-resolution diagnostic and intraoperative images and illustrates the importance of rapid diagnosis and recognition of the potentially complex nature of the aortic dissection to avoid impending hemodynamic deterioration.

Late Transcatheter Aortic Valve Thrombosis Leading to Cardiogenic Shock

A 67-year-old woman with prior transcatheter aortic valve replacement presented with worsening dyspnea. Imaging revealed transcatheter aortic valve thrombosis and aortic stenosis. Despite oral anticoagulation, she progressively deteriorated and developed cardiogenic shock. We highlight the Heart Team's role in treating this unusual late thrombosis. (Level of Difficulty: Intermediate.).

Surgical Salvage of Annular Rupture After Transcatheter Aortic Valve Implantation by Conversion Into Annular Enlargement

We describe an 88-year-old woman who experienced annular rupture during transcatheter aortic valve replacement despite preventative measures. She underwent Y incision and rectangular patch for the double purpose of repairing the rupture and enlarging the aortic root. We highlight the heart team's role in confronting this potentially catastrophic complication. (Level of Difficulty: Advanced.).

Renal Dysfunction in Patients with Left Ventricular Assist Device

Late-stage heart failure and renal dysfunction are often seen in conjunction. Cardiorenal syndrome (CRS) describes the complex interaction between the two disease states. Early literature described the pathophysiology of CRS as related only to reduced cardiac output and decreased renal perfusion. Recent literature suggests a more multifaceted mechanism. Left ventricular assist devices (LVAD), used as bridge-to-transplant and destination therapy in patients with heart failure, impact not only cardiac function but also renal function, especially in those patients with preoperative renal dysfunction. The mechanism by which LVAD implantation affects renal function is complex and understated in early literature. In this review, we discuss the pathogenesis of CRS, the impact of preoperative renal dysfunction in patients undergoing LVAD implantation, and the effect of LVAD implantation on postoperative renal function.

Papillary Fibroelastoma Incidentally Found on Left Atrial Wall During Minimally Invasive Aortic Valve Replacement

A 60-year-old man was about to undergo minimally invasive aortic valve replacement when transesophageal echocardiography revealed an intracardiac mass on the left atrial free wall. Multimodal images from 5 months earlier had shown no mass. We converted the procedure to open surgery. The excised mass resembled a cardiac myxoma but was determined to be a papillary fibroelastoma. This case illustrates that papillary fibroelastomas can form and grow rapidly, warranting alertness for their unexpected discovery before and during cardiac surgical procedures.

Tissue plasminogen activator in left ventricular assist device-related intravascular hemolysis after failed augmented anticoagulation

OBJECTIVES

We sought to examine the efficacy and safety of adding fibrinogen-guided low-dose multi-day Alteplase™ tissue plasminogen activator (tPA) in the management of intravascular hemolysis (IVH) in patients with the HeartMate II (HM-II) continuous flow (CF) left ventricular assist device (LVAD) who failed to achieve IVH resolution with conventional augmented anticoagulation (AAC).

BACKGROUND

IVH in patients with LVAD is often treated with AAC, failing which pump exchange is considered. We hypothesized that a trial of low-dose tPA after failed AAC therapy could resolve IVH and prevent pump exchange in some patients.

METHODS

We performed a retrospective study of 31 HM-II CF LVAD patients admitted to our center from January 2015 to January 2020 for IVH management who received tPA following failed AAC. Primary 6-month outcomes included successful IVH resolution, unsuccessful IVH resolution requiring pump exchange, gastrointestinal bleeding, ischemic and hemorrhagic cerebrovascular accident (CVA), and death.

RESULTS

Thirty-one patients with IVH were treated with tPA following failed AAC. Successful resolution of IVH occurred in 22/31 (71%) patients. Pump exchange occurred in 9/31 (29%) patients. Gastrointestinal bleeding occurred in 7/31 (22.6%) patients. Ischemic CVA occurred in 6/31 (19.4%) patients.

CONCLUSIONS

Management of IVH with administration of low-dose tPA after failed AAC is feasible and may prevent pump exchange in some patients.

Acute mitral valve regurgitation secondary to papillary muscle rupture due to infective endocarditis

BACKGROUND

Papillary muscle rupture due to infective endocarditis is a rare event and proper management of this condition has not been described in the literature. Our case aims to shed light on treatment strategies for these patients using the current guidelines.

CASE PRESENTATION

This case presents a 58-year-old male with acute heart failure secondary to papillary muscle rupture. He underwent an en bloc resection of his mitral valve with a bioprosthetic valve replacement. Specimen pathology later showed necrotic papillary muscle due to infective endocarditis. The patient was further treated with antibiotic therapy. He recovered well post-operatively and continued to do well after discharge.

CONCLUSION

In patients who present with papillary muscle rupture secondary to infective endocarditis, clinical symptoms should drive the treatment strategy. Despite the etiology, early mitral valve surgery remains treatment of choice for patients who have papillary muscle rupture leading to acute heart failure. Culture-guided prolonged antibiotic treatment is vital in this category of patients, especially those who have a prosthetic valve implanted.

Giant right coronary artery to coronary sinus fistula

BACKGROUND

We describe a giant right coronary artery (RCA) to coronary sinus (CS) fistula in a 59-year-old woman who presented to our institution with right heart enlargement.

METHODS

Investigation revealed an ectatic 22mm RCA draining into an enlarged CS, and a Qp:Qs of 2.0. We proceeded with surgery. After initiating cardiopulmonary bypass and electrical arrest, the distal RCA was opened. An opening into the CS was confirmed and closed with a bovine pericardium patch. The RCA origin was triply ligated. Anastomoses of a saphenous vein graft to the posterior descending artery and the right ventricular marginal artery were performed, followed by anastomosis to the ascending aorta.

RESULTS

Post-operatively, mixed venous oxygen saturation was 76%. Six months later the patient was doing well.

CONCLUSION

Coronary artery fistulas are rare congenital anomalies for which the ideal management strategies remain under study, with surgical repair being the mainstay of treatment in complex, aneurysmal fistulas.

PFO Closure after Pulmonary Valve Intervention in Patients with Hypoxemia Due to Right-to-Left Intracardiac Shunt

Four patients with pulmonary valve (PV) disease and patent foramen ovale (PFO) presented with dyspnea on exertion. Work-up revealed hypoxemia secondary to right-to-left intracardiac shunt. We demonstrate that correction of the primary culprit right heart overload lesion via PV replacement enabled safe PFO repair and resolution of hypoxemia.

Atypical Presentation of Right Ventricular Cardiac Hamartoma in a Young Man

Cardiac tumors in adults are exceedingly rare and usually benign. We describe a 29-year-old man with a previous diagnosis of interventricular septal hypertrophy who presented with increasing severity of dyspnea and fatigue. Work-up revealed a 4.9 × 3.7 cm mass at the base of the interventricular septum. Biopsy revealed a benign cardiac hamartoma atypically located in the right ventricle, and the mass was resected via right ventriculotomy.

Cone-Beam CT and Image Fusion-Guided Percutaneous Recanalization of Occluded Central Venous Stent

We describe an 81-year-old man with end-stage renal disease and central venous occlusion who was referred for dialysis access creation. This case illustrates a novel percutaneous image fusion–guided recanalization of an occluded right subclavian vein and brachiocephalic vein stent in a patient with limited remaining dialysis access sites. (Level of Difficulty: Advanced.)

Ventricular Fibrillation Arrest and Pulmonary Homograft Rupture During Transcatheter Pulmonary Valve: Successful Rescue by Heart Team

We describe a 31-year-old woman with pulmonary homograft rupture and ventricular fibrillation arrest complicating a transcatheter pulmonary valve (TPV) procedure. She underwent extracorporeal membrane oxygenation (ECMO) with immediate surgical repair including bioprosthetic pulmonary valve replacement. She had difficulty weaning off ECMO due to hyperacute failure of the valve and ultimately underwent successful hybrid TPV with complete recovery. This case illustrates the importance of the heart team approach during catheter and surgical interventions in adult congenital heart disease.

Large, Hormonally Active Primary Cardiac Paraganglioma: Diagnosis and Management

We describe a 26-year-old woman presenting with chest pain and evidence of coronary ischemia. Echocardiography revealed a large left ventricular mass initially deemed unresectable at her initial institution. Investigation revealed a dopamine-secreting primary cardiac paraganglioma (PCP) encompassing vital cardiac architecture. This case discusses our heart team approach to complex cardiac masses and illustrates the feasibility of surgical resection in complex cases of hormonally active PCPs.

Successful coil embolization of a large right coronary artery-coronary sinus fistula causing a significant left-to-right shunt: a case report

Background

This case reviews a challenging but successful transcatheter coil embolization of a large congenital coronary artery fistula (CAF) causing a significant left-to-right shunt.

Case summary

A 51-year-old female with no significant prior history presented with symptoms of dyspnoea and chest discomfort. Extensive evaluation revealed a large CAF between a tortuous right coronary artery (RCA) and the coronary sinus (CS) composed of three aneurysmal pseudochambers. Closure of the RCA-CS fistula was attempted through coil deployment into the fistula neck. However, due to the brisk flow through the fistula, both coils embolized into the fistula sac. An alternative location was subsequently identified on three-dimensional rendering of a computed tomography angiography scan, which revealed a sharp bend in the RCA prior to the fistula neck and distal to the posterior descending artery (PDA) takeoff. Repeat attempt at embolization was accomplished using a telescoping system to reach and occlude the targeted bend. The coil mass remained stable and angiography demonstrated reduced flow through the fistula and preserved patency of the PDA. The decreased residual flow through the fistula secondary to the initial embolization attempt likely aided the successful deployment of coils in the second and final attempt. At 1 year, the patient was doing well with resolution of her symptoms and no clinical symptoms of coronary ischaemia.

Discussion

We suggest that an initial unsuccessful attempt at transcatheter embolization of a CAF should not preclude subsequent attempts for closure when there exists an appropriate indication.

CT-Guided Endovascular Exclusion of Pseudoaneurysmal Subclavian Bypass After Early-Age Surgical Correction of Complex Aortic Coarctation

We describe a 64-year-old woman with subclavian pseudoaneurysm after aortic coarctation repair, treated using a hybrid approach involving true three-dimensional analysis and image fusion-guided placement of thoracic endovascular aortic repair stents. This case illustrates the potential complications of coarctation repair and need for lifelong surveillance in these patients. (Level of Difficulty: Advanced.)