Invasive hemodynamic assessment of patients with submassive pulmonary embolism.

OBJECTIVES: To investigate the invasive hemodynamics in patients with intermediate-risk pulmonary embolism (PE) and the change that occurs with catheter-directed thrombolysis (CDT). BACKGROUND: Intermediate-risk PE is associated with right ventricular strain and worse outcomes yet the invasive hemodynamics have not been well described. METHODS: Ninety-two consecutive patients with intermediate-risk PE referred for CDT at two tertiary medical centers with Pulmonary Embolism Response Teams were included in this prospective cohort study. Hemodynamics at baseline and after CDT therapy was measured. Patients with cardiac index (CI) ≤1.8 L min-1 m-2 were compared to those without shock (CI > 1.8). Linear regression analysis was performed to study the relationship between clinical variables and low CI. RESULTS: Thirty-seven out of 92 (40%) had a CI less than 1.8 L min-1 m-2 . When comparing the low CI to the normal CI groups, most demographics, vital signs, biomarkers, and PE severity index (PESI) scores were similar. The low CI group had more females and slightly lower systolic blood pressures although still in the normal range (122 vs. 132 mmHg, p = .026). Treatment with CDT was associated with significant improvement in CI, heart rate, and pulmonary artery pressures in both groups. Linear regression analysis did not reveal a strong correlation between CI and noninvasive metrics such as heart rate, blood pressure, or PESI score. CONCLUSIONS: Forty percent of patients with submassive PE had a depressed CI and treatment with CDT lead to hemodynamic improvements. Invasive hemodynamics may help better identify higher risk patients and guide therapy.

Postoperative outcomes and management strategies for coronary artery disease in patients in need of a lung transplantation.

BACKGROUND: Patients requiring lung transplantation (LTx) may also have coronary artery disease (CAD). The peri-operative management and long-term outcomes of these patients are not well established. METHODS: Patients referred for LTx from 2008 to 2014 were included in this study. CAD was defined by angiography as no CAD (stenosis <20%), moderate CAD (20%-69%), and significant CAD (stenosis ≥70%). Revascularization was per recommendations of local heart team. Postoperative cardiovascular outcomes and long-term survival are reported. RESULTS: A total of 1493 patients were screened for LTx during this period and 656 received a transplant. Of the patients that underwent LTx, 51% had no CAD, 33% had moderate non-obstructive CAD, and 16% had obstructive CAD. Forty-three patients underwent revascularization. There was a no increased risk of peri-operative cardiovascular events or for adjusted mortality for patients with obstructive CAD (HR=1.24, 95% CI: 0.83-1.86, P=.290) including those requiring revascularization. CONCLUSIONS: There is a high prevalence of coronary disease in the population of patients with advanced lung disease requiring lung transplantation. Careful evaluation and treatment can allow for patients with all severities of CAD including those requiring revascularization to successfully undergo LTx.

Assessment of P2Y12 inhibitor usage and switching in acute coronary syndrome patients undergoing percutaneous coronary revascularization.

BACKGROUND: Dual antiplatelet therapy is recommended for patients with acute coronary syndrome (ACS) that undergo percutaneous coronary intervention (PCI). However, the effect of switching P2Y12 inhibitors between the loading dose and therapy after discharge is not well described. METHODS: This post-hoc analysis of a prospectively collected registry included 3219 consecutive ACS patients who underwent PCI. Patients were categorized into four groups: clopidogrel at load and discharge (C-C), loading dose of clopidogrel and discharged on prasugrel/ticagrelor (C-PT), loading dose of prasugrel/ticagrelor and discharged on clopidogrel (PT-C), and prasugrel/ticagrelor at load and discharge (PT-PT). RESULTS: While 77.6% of patients received the C-C treatment regimen and 13.6% received the PT-PT strategy, the strategy of P2Y12 switching was fairly common with 6.2% in the PT-C group and 2.6% in the C-PT group. While C-C was the most common treatment regimen, PT-C and PT-PT were more commonly used in STEMI patients than in NSTEMI or unstable angina patients. A significantly lower unadjusted incidence of the composite outcome (death, MI, and repeat revascularization) was appreciated in both the PT-C (1.0%) and PT-PT (2.3%) groups than the C-C group (4.0%). Propensity-score matched analysis still showed significantly reduced risk (HR=0.22, 95% CI 0.05-0.93, p=0.04) in the PT-C group vs. a matched group of C-C controls. CONCLUSIONS: The strategy of utilizing a newer P2Y12 inhibitor and then switching to clopidogrel in ACS patients following PCI is used with some frequency in routine clinical practice and further studies should evaluate the safety and efficacy of such a strategy.

Identification of Intrastent Pathology Associated With Late Stent Thrombosis Using Optical Coherence Tomography.

OBJECTIVE: To better characterize intrastent pathology using optical coherence tomography (OCT) in patients presenting with late and very late stent thrombosis (LST/VLST). BACKGROUND: The contribution of specific intrastent pathologies to the development of LST/VLST is not well understood. METHODS: In this single-center, retrospective, observational study of 796 consecutive patients treated for ST-segment elevation myocardial infarction (STEMI) with primary PCI we identified 57 patients (7.2%) in whom STEMI resulted from LST/VLST. Of the patients with LST/VLST, 21 patients (37%) had OCT performed at the discretion of the operator during PCI for LST/VLST. Independent reviewers performed qualitative offline analysis of OCT images to determine the cause of stent thrombosis defined as the specific intrastent pathology associated with thrombus deposition. RESULTS: The principal intrastent pathology causing LST/VLST was determined to be stent malapposition in 11 patients (55%), of which 5 (25% of all LST/VLST patents) had findings suggestive of positive vessel remodeling. Neoatherosclerosis was determined to be the cause of LST/VLST in 7 patients (35%). LST/VLST resulted from uncovered stent struts in 2 patients (10%). Among all LST/VLST patients, in-hospital mortality (12.3%) and post-hospital target vessel failure (TVF) or cardiac death (21.7%, median follow-up 1.6 years) remained high. There was a trend towards decreased TVF or cardiac death (7.7% vs. 27.3% P = 0.24) in patients who underwent OCT-guided therapy. CONCLUSIONS: LST/VLST remains a significant cause of STEMI and is associated with considerable morbidity and mortality. OCT use at the time of PCI consistently identifies significant intrastent pathology with potentially meaningful clinical impact.

Extracorporeal membrane oxygenation support in acute coronary syndromes complicated by cardiogenic shock.

BACKGROUND: Acute coronary syndrome (ACS) complicated by shock is associated with high mortality despite the use of percutaneous support devices. Extracorporeal membrane oxygenation (ECMO) offers cardiopulmonary support but its safety and efficacy in the ACS setting is still under investigation. METHODS: We reviewed the clinical characteristics and course of 18 consecutive patients who received femoral veno-arterial ECMO in the cardiac catheterization lab for severe shock due to ACS at our center between 2007 and 2013. RESULTS: The average age was 59.9 years, 72.2% male. Of the 18 patients, 83% had a ST-segment elevation myocardial infarction, of which 55% had a left main or left anterior descending artery occlusion. Thirteen patients received stents, three were referred for coronary artery bypass grafting alone, and two received balloon angioplasty. All patients received aspirin, a thienopyridine (either clopidogrel or ticagrelor), and heparin. Five patients received a glycoprotein IIb/IIIa inhibitor during the catheterization. The average length of ECMO was 3.2 ± 2.5 days, length of stay was 23.4 days, and 67% survived to discharge. Seventeen of eighteen patients (94%) required at least one blood transfusion and use of blood products was significantly higher in the group receiving glycoprotein IIb/IIIa inhibitors [19 U of packed red blood cells (PRBC) vs. 8.2 U (P = 0.003)]. CONCLUSIONS: In patients with severe shock or refractory ventricular arrhythmias due to ACS, VA-ECMO likely offers an alternative form of biventricular support albeit with significant resource utilization and morbidity. A better understanding of how to manage patients with ACS requiring VA-ECMO support including the associated morbidities such as bleeding is necessary.

Optical coherence tomography for characterization of cardiac allograft vasculopathy after heart transplantation (OCTCAV study).

BACKGROUND: Optical coherence tomography (OCT) is a novel intravascular imaging modality with excellent spatial resolution. This study explored the utility of OCT in cardiac transplantation for the detection and characterization of early changes associated with coronary allograft vasculopathy (CAV). METHODS: Fifteen consecutive patients, 1 to 4 years after transplant with no angiographic evidence of CAV, underwent successful OCT imaging using the Fourier-domain OCT system (C7-XR, St. Jude Medical, St. Paul, MN) in the left anterior descending artery. Analysis included measurements of the lumen, intima, and media layers, and characterization of atherosclerotic plaques. Patients were stratified by intima-to-media (I/M) ratio and classified as normal (≤1) or abnormal (>1). RESULTS: Patients were a mean of 2.8 years after transplant, 58 years old, and 92% were men. OCT imaging revealed 8 of 15 patients had intimal hyperplasia with an I/M ratio >1. Comparing those with I/M ratio of ≤1 and >1, the median (interquartile range) intimal thickness was greater (75 [70-101] vs 206 [97-269]µm, p = 0.03), whereas the media thickness was no different (72 [70-103] vs 94 [73-113]µm, p = 0.53). In addition, 7 of 15 patients had lipid-rich or calcified atherosclerotic plaques. CONCLUSIONS: OCT provides high-resolution quantitative imaging of the coronary arteries and its use allows for detailed assessment of the coronary artery wall and early morphologic changes that occur after cardiac transplantation. The clinical predictive value of these OCT-derived measurements remains to be determined.

Long-term effects on renal function of dose-reduced calcineurin inhibitor and sirolimus in cardiac transplant patients.

UNLABELLED: Calcineurin inhibitor (CNI)-associated renal insufficiency is common after cardiac transplantation (CTX); however, the addition of sirolimus allows for CNI dose reduction and this strategy may limit CNI renal toxicity. This study examines the long-term effects of such a strategy. METHODS: Patients from a single center who had CTX from 1990 to 2007 and who were converted to sirolimus and a dose-reduced CNI were compared to group-matched controls maintained on CNI and an antiproliferative agent. RESULTS: One hundred and fifty-five patients (79 sirolimus and 76 controls) were included and had similar baseline characteristics. Sirolimus was started a mean of 1429 d post-CTX and maintained for a mean of 823 d. Reason for conversion to sirolimus was renal insufficiency (34%), vasculopathy (29%), recurrent rejection (19%), and other (18%). The eGFR was not different between groups at baseline (44.7 mL/min/1.73 m(2) vs. 46.0, p = 0.64) or at any point during follow-up: 90 d, 180 d, 1 yr, 2 yr, and 3 yr. conclusion: Patients converted to a regimen of sirolimus and a dosed-reduced CNI have stable renal function over the following three yr, but do not have an improvement in renal outcomes compared to patients maintained on full dose CNI.