Hemodynamic compromise in pulmonary embolism: "A tale of two ventricles".

In acute pulmonary embolism (PE), low cardiac output (CO)-hypotension results from disparate ventricular conditions: The left ventricle (LV) is under-filled and contracting vigorously, whereas the right ventricle (RV) is failing and dilated. The proximate cause of LV preload deprivation is thrombus-induced pulmonary vascular obstruction; abruptly increased pulmonary vascular resistance (PVR) induces acute RV systolic dysfunction which further compromises trans-pulmonary flow. "Escalation of Care" interventions (thrombolytics and aspiration thrombectomy) improve systemic hemodynamics by increasing LV preload delivery directly by reducing PVR and indirectly by relief of the strained failing RV.

Disparate impact of severe aortic and mitral regurgitation on left ventricular dilation.

In asymptomatic severe aortic (AR) and mitral regurgitation (MR), left ventricular (LV) dimension criteria were established to guide timing of valve replacement to prevent irreversible LV dysfunction. Given both lesions are primary LV volume overload ''leaks'', it might be expected that both lesions would induce similar impact on the LV and result in equivalent dimension criteria for intervention. However, the dimension-based intervention criteria for AR versus MR (developed through natural history studies), differ markedly. The pathophysiological foundations for such discordance have neither been fully elucidated nor emphasized. This case-based treatise compares the two regurgitant lesions with respect to: (a) ''total regurgitant circuits''; (b) ''driving pressures'' resulting in LV volume overload from each respective ''leak''; and (c) volume and afterload wall stresses imposed on the LV.Key points The ''total circuits'' of volume overload differ: The AR circuit includes the LV and systemic vasculature, whereas MR includes the LV ejecting into the left atrium/pulmonary veins and systemic circulation. The ''driving pressure'' of regurgitation and afterload are high with AR and low with MR. Differing ''total circuits'' and ''driving pressures'' impose disparate wall stresses upon the LV. Parallel and serial sarcomere replication occurs in AR, while only serial replication occurs in MR. It therefore follows that for regurgitation of similar severities, AR results in greater LV dilation at the point of irreversible myocardial dysfunction compared to MR. These considerations may explain, at least in part, the disparate dimension criteria employed for valve intervention for severe AR vs MR.

Impella RP for treatment of right ventricular shock: Appropriate unloading never gets old.

Rapid restoration of hemodynamics is key to successful shock management. The failing right ventricular (RV) is resilient and recovers if hemodynamics are supported while the underlying insulting cause is alleviated. Inotropic/vasopressor drugs constitute a "double-edged sword" that augment hemodynamics, but exacerbate myocardial and multiorgan injury. Impella RP mechanical support for RV shock stabilizes hemodynamics and is associated with favorable clinical outcomes.

Hemodynamics of constrictive pericarditis and restrictive cardiomyopathy.

Constrictive pericarditis (CP) and restrictive cardiomyopathy (RCM) are indolent disabling diseases of diastolic function. The two conditions share common pathophysiologic features, resulting in similar and overlapping clinical presentations, echocardiographic findings, and hemodynamic characteristics. However, their clinical course differs, as CP is surgically curable whereas RCM is a chronic condition managed medically. Separating these two entities is based on delineation of anatomic and physiologic derangements employing multimodality hemodynamic interrogation by advanced imaging techniques (Echo-Doppler, CT, and especially MRI) combined with sophisticated invasive hemodynamics.

Urgent mechanical circulatory support and transcatheter mitral valve repair for refractory hemodynamic compromise.

Patients presenting with hemodynamic instability attributable to left ventricular systolic dysfunction and concomitant severe mitral regurgitation (MR) are increasingly recognized and pose complex management challenges. Surgical therapy is typically precluded owing to prohibitive mortality. The role of percutaneous mechanical circulatory support in such cases is well established; however, such interventions may be neither sufficient to achieve optimal stability nor prove definitive. The advent of novel catheter-based mitral repair modalities now offers primary decisive therapeutic intervention. Three cases of cardiogenic shock with severe MR illustrate the salutary hemodynamic and clinical responses to percutaneous mechanical support and valve repair by mitral clip.

Low-dose systemic thrombolytic therapy for treatment of submassive pulmonary embolism: Clinical efficacy but attendant hemorrhagic risks.

OBJECTIVES: The purpose of the present study is to evaluate the safety and efficacy of "low-dose" systemic thrombolytic therapy (TT) for treatment of patients with intermediate-high risk submassive pulmonary embolism (PE). BACKGROUND: TT is increasingly utilized in acute submassive PE. Strategies for TT include catheter-directed administration as well as traditional IV systemic therapy. Regardless of the route, most studies document the attendant significant bleeding complication rates expected from induction of a systemic lytic state. To mitigate bleeding, "low-dose" systemic TT (Alteplase 50 mg) has been advocated, based on recent studies which demonstrated clinical efficacy with elimination of any significant bleeding complications. METHODS: Over a 24-month period, our institutional PE Response Team treated 45 acute submassive PE patients with "Low Dose" IV Alteplase 50 mg. Clinical outcomes and bleeding complications were assessed. RESULTS: Overall clinical outcome was excellent, with 97.8% of patients surviving to discharge and a 30-day, all-cause mortality of 4.4%. Despite no patients having a HAS-BLED score > 2 (average score = 0.8 +/-), ISTH major and GUSTO moderate bleeding was observed in 11% (n = 5) of cases. CONCLUSIONS: The present observations document that low-dose systemic TT is associated with excellent clinical outcome for intermediate-high risk submassive PE, but with attendant risk for bleeding. These findings are consistent with the concept that induction of a therapeutic lytic state carries inextricable bleeding risk.

Ultrasound-accelerated thrombolysis (USAT) versus standard catheter-directed thrombolysis (CDT) for treatment of pulmonary embolism: A retrospective analysis.

Ultrasound-accelerated thrombolysis (USAT) is advocated in pulmonary embolism (PE) based on the hypothesis that adjunctive ultrasound provides superior clinical efficacy compared to standard catheter-directed thrombolysis (CDT). This retrospective study was designed to compare outcomes between the two modalities. We analyzed patients with computed tomography-diagnosed PE at our institution treated with either USAT or standard CDT. Efficacy parameters assessed included invasive pulmonary artery systolic pressure (PASP; pre- and 24 hours post-treatment), non-invasive right-to-left ventricle (RV/LV) ratio (pre- and post-treatment), and general clinical outcomes (length-of-stay, significant bleeding, and mortality). We analyzed 98 cases (62 USAT and 36 CDT), in whom massive PE was diagnosed in 7%, intermediate/high risk in 81%, and intermediate/low risk in 12%. Overall, 92% had bilateral clot and 40% saddle embolus. At 24 hours, PASP decreased similarly in both groups (CDT Δ14.7 mmHg, USAT Δ10.8 mmHg; p = 0.14). Post-treatment, CDT showed similar improvement in the RV/LV ratio (CDT Δ0.58 vs USAT Δ0.45; p = 0.07), despite the baseline ratio being greater in the CDT group, indicating more severe RV strain (1.56 ± 0.36 vs 1.40 ± 0.29; p = 0.01). Intensive care unit and hospital length-of-stays were similar in both groups. A trend toward lesser significant bleeding rates in the CDT group (8.3% vs 12.9%, p = 0.74) as well as improved survival-to-discharge (97.2% vs 91.9%, p = 0.66) was observed. Compared to USAT, standard CDT achieves similar beneficial effects on hemodynamics, RV/LV ratios, and clinical outcomes. These observations suggest that salutary clinical results may be achieved without the need for very expensive devices.

Maintenance of valvular integrity with Impella left heart support: Results from the multicenter PROTECT II randomized study.

BACKGROUND: The Impella 2.5 axial flow pump, which is positioned across the aortic valve, is widely employed for hemodynamic support. The present study compared structural and functional integrity of the left heart valves in patients undergoing Impella vs intra-aortic balloon pump in the randomized PROTECT II trial. METHODS AND RESULTS: Transthoracic echocardiograms were performed at baseline, 1 and 3 months in 445 patients in the PROTECT II trial. Serial studies were analyzed by an independent echocardiography core laboratory for aortic and mitral valve structure and function, and left ventricular ejection fraction (LVEF). During Impella support there was no appreciable change in the degree of baseline valvular regurgitation. There were no cases of structural derangement of the mitral or aortic valve after use of the Impella device. At 90-day follow-up, there was an average 22% relative increase in LVEF from baseline (27% ± 9 vs. 33% ± 11, P < 0.001). CONCLUSIONS: The present echocardiographic analysis of the PROTECT II study confirms prior observations regarding the safety of the Impella 2.5 device with respect to mitral and aortic valve function.

Occupational health hazards in the interventional laboratory: Time for a safer environment.

Over the past 30 years, the advent of fluoroscopically guided interventional procedures has resulted in dramatic increments in both X-ray exposure and physical demands that predispose interventionists to distinct occupational health hazards. The hazards of accumulated radiation exposure have been known for years, but until recently the other potential risks have been ill-defined and under-appreciated. The physical stresses inherent in this career choice appear to be associated with a predilection to orthopedic injuries, attributable in great part to the cumulative adverse effects of bearing the weight and design of personal protective apparel worn to reduce radiation risk and to the poor ergonomic design of interventional suites. These occupational health concerns pertain to cardiologists, radiologists and surgeons working with fluoroscopy, pain management specialists performing nonvascular fluoroscopic procedures, and the many support personnel working in these environments. This position paper is the work of representatives of the major societies of physicians who work in the interventional laboratory environment, and has been formally endorsed by all. In this paper, the available data delineating the prevalence of these occupational health risks is reviewed and ongoing epidemiological studies designed to further elucidate these risks are summarized. The main purpose is to publicly state speaking with a single voice that the interventional laboratory poses workplace hazards that must be acknowledged, better understood and mitigated to the greatest extent possible, and to advocate vigorously on behalf of efforts to reduce these hazards. Interventional physicians and their professional societies, working together with industry, should strive toward the ultimate zero radiation exposure work environment that would eliminate the need for personal protective apparel and prevent its orthopedic and ergonomic consequences. © 2008 Wiley-Liss, Inc.

Peri-procedural myocardial infarction: Plaques and patients "at-risk".

Patients with acute coronary syndrome are at risk for peri-procedural myocardial infarction (PMI) Lipid-laden plaques with thinned disrupted fibrous caps are most prone to PMI PMI is associated with worse outcome over time, though whether such damaging events are causal or instead reflect patients prone to future instability from non-culprit vulnerable plaques requires further delineation.

Hemodynamic guidance of mitral paravalvular leak closure: The V is the key.

Severe mitral paravalvular leak (PVL) induces elevated mean left atrial (LA) pressure (LAP) and prominent V waves, leading to pulmonary hypertension and right heart failure PVL closure promptly reduces V wave and mean LAP, correlates with improved echo regurgitation grade, and exerts immediate benefit to the lungs and right heart Hemodynamic response patterns facilitate PVL closure.

Severe mitral regurgitation and biventricular heart failure successfully treated with biventricular percutaneous axial flow pumps as a bridge to mitral valve surgery.

Prompt recognition of acute right ventricular failure is essential in order to provide timely hemodynamic support. We report a case of a patient with severe mitral regurgitation complicated by cardiogenic shock that failed to improve with left ventricular support alone. The recognition of concomitant right ventricular failure led to the addition of a right ventricular support device, resulting in dramatic hemodynamic improvement. © 2016 Wiley Periodicals, Inc.

Invasive characterization of atherosclerotic plaque in patients with peripheral arterial disease using near-infrared spectroscopy intravascular ultrasound.

OBJECTIVES: We describe the characteristics of atherosclerotic plaque in patients with peripheral arterial disease (PAD) using near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) BACKGROUND: Imaging and autopsy studies have described atherosclerotic plaque in different vascular beds, including varying degrees of lipid, fibrosis, and calcification. Recently, NIRS has been validated as an accurate method for detecting lipid-core plaque (LCP) in the coronary circulation. Invasive evaluation of plaque composition using NIRS-IVUS has not been reported in different peripheral arterial circulations. METHODS: We performed invasive angiography and NIRS-IVUS in consecutive PAD patients prior to percutaneous revascularization. Imaging evaluation included parameters from angiography, IVUS, and NIRS. NIRS-IVUS findings were compared among different vascular beds with regard to the presence and extent of calcification and LCP. RESULTS: One hundred and forty-nine lesions in 126 PAD patients were enrolled, including the internal carotid (n = 10), subclavian/axillary (n = 9), renal (n = 14), iliac (n = 35), femoropopliteal (n = 69), and infrapopliteal (n = 12) arteries. Plaque morphology was calcified in 132 lesions (89%) and fibrous in 17 lesions (11%). Calcification varied from 100% of renal artery stenoses to 55% of subclavian/axillary artery stenoses. LCP was present in 48 lesions (32%) and prevalence varied from 60% in carotid artery stenoses to 0% in renal artery stenoses (P < 0.005). LCP was only observed in fibrocalcific plaque, and was longitudinally and circumferentially surrounded by a more extensive degree of calcium. CONCLUSIONS: NIRS-IVUS in stable PAD patients demonstrates a high frequency of calcific plaque and statistically significant differences in the frequency of LCP in different arterial beds. LCP, when present in the peripheral circulation, is always associated with calcified plaque. The strong co-localization of calcified plaque and LCP in severe PAD lesions may provide plaque-stabilizing effects; further studies are needed. © 2017 Wiley Periodicals, Inc.

"Cardio-Oncology": Implications for interventionists.

CV complications in cancer patients predominantly result from collateral damage from chemotherapy and radiation Complex interplay of manifold pathophysiologic processes poses evaluation challenges and management conundrums. Pre-cath planning essential, employing advanced non-invasive imaging of myocardium, PC, and great vessels.

Stenting precision: "Image small, miss small".

Stenting by angiography alone predisposes to geographic miss STEMI culprit lesions are most susceptible to Geographic Miss Direct coronary imaging assures procedural precision and perfection.

Invasive evaluation of plaque morphology of symptomatic superficial femoral artery stenoses using combined near-infrared spectroscopy and intravascular ultrasound.

The purpose of this study is to characterize the plaque morphology of severe stenoses in the superficial femoral artery (SFA) employing combined near-infrared spectroscopy and intravascular ultrasound (NIRS-IVUS). Atherosclerosis is the most common cause of symptomatic peripheral arterial disease. Plaque composition of SFA stenoses has been characterized as primarily fibrous or fibrocalcific by non-invasive and autopsy studies. NIRS has been validated to detect lipid-core plaque (LCP) in the coronary circulation. We imaged severe SFA stenoses with NIRS-IVUS prior to revascularization in 31 patients (46 stenoses) with Rutherford claudication ⩾ class 3. Angiographic parameters included lesion location and stenosis severity. IVUS parameters included plaque burden and presence of calcium. NIRS images were analyzed for LCP and maximum lipid-core burden index in a 4-mm length of artery (maxLCBI4mm). By angiography, 38 (82.6%) lesions were calcified and 9 (19.6%) were chronic total occlusions. Baseline stenosis severity and lesion length were 86.0 ± 11.0% and 36.5 ± 46.5 mm, respectively. NIRS-IVUS identified calcium in 45 (97.8%) lesions and LCP in 17 (37.0%) lesions. MaxLCBI4mm was 433 ± 244. All lesions with LCP also contained calcium; there were no non-calcified lesions with LCP. In conclusion, this is the first study of combined NIRS-IVUS in patients with PAD. NIRS-IVUS demonstrates that nearly all patients with symptomatic severe SFA disease have fibrocalcific plaque, and one-third of such lesions contain LCP. These findings contrast with those in patients with acute coronary syndromes, and may have implications regarding the pathophysiology of atherosclerosis in different vascular beds.