Initial experience with a continuous mechanical aspiration system for thrombus removal before percutaneous coronary intervention.

OBJECTIVES: Here we investigate the safety and efficacy of a continuous mechanical aspiration system when used before percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS). BACKGROUND: Historically, trials of routine manual aspiration thrombectomy in ACS patients have reported mixed results. This may be due to the technical limitations of manual aspiration, which suffers from decreasing vacuum power as aspiration is performed. METHODS: This is a retrospective case series of all patients treated with continuous mechanical aspiration (Indigo CAT RX Aspiration System; Penumbra Inc.) before PCI between August 2017 and July 2020 at five centers in the United States. Data regarding angiographic assessments, procedure, and safety were examined. RESULTS: Seventy-two patients (mean age 60 ± 12.5 years, 34.7% female) with ST Elevation Myocardial Infarction (STEMI) (80.6%) or Non-ST Elevation Myocardial Infarction (NSTEMI) (19.4%) were included. Target vessels were the right coronary (43.1%), left anterior descending (33.3%), and left circumflex (23.6%). Preprocedure, 94.4% had a high thrombus burden (thrombolysis in myocardial infarction [TIMI] thrombus grade ≥ 3). Median aspiration time was 35 s and median access-to-reperfusion time was 10 min. After CAT RX alone, 86.1% had complete perfusion (TIMI flow grade 3). After the procedure, 94.4% had TIMI thrombus grade <3% and 97.2% had TIMI flow grade 3. There were no cases of ischemic stroke. Cardiovascular mortality at 30 days was 1.4%. CONCLUSIONS: In our initial experience, aspirating thrombus from ACS patients using the Indigo CAT RX Aspiration System before PCI was safe and effective for reducing thrombus burden and restoring flow.

Vasopressors independently associated with mortality in acute myocardial infarction and cardiogenic shock.

BACKGROUND: Increasing vasopressor dose is associated with increasing mortality in patients presenting with acute myocardial infarction and cardiogenic shock (AMICS). It is unknown whether the use of vasopressors is independently harmful or if their use is secondary to decreasing intrinsic cardiac power output (CPO). Mechanical circulatory support (MCS) devices enhance CPO. We sought to evaluate the independent impact of increasing vasopressor dose on survival in the National Cardiogenic Shock Initiative (NCSI). METHODS: The NCSI is a single arm prospective trial evaluating outcomes associated with the use of MCS using Impella in patients with AMICS. Early initiation of MCS placement before percutaneous coronary intervention (PCI) and rapid de-escalation of vasopressors guided by systematic use of invasive hemodynamic measures led to 70% in-hospital survival for the first 300 patients enrolled from July 2016 to December 2019 in 57 U.S. sites. RESULTS: Hemodynamic measures were obtained immediately after MCS and PCI. Survival curves were constructed based on CPO and use of vasopressors. For patients with CPO ≤0.6 W, survival was 77.3%, 45.0%, and 35.3% when 0, 1, or ≥ 2 vasopressors were used (p = 0.02). Similarly, for patients with CPO >0.6 W survival was 81.7%, 72.6%, and 56.8%, respectively (p = 0.01). Logistic regression analysis demonstrated that increasing vasopressor requirements were independently associated with increasing mortality (p = 0.02). CONCLUSION: Increasing vasopressor requirement is associated with increased mortality in AMICS independent of underlying CPO. Methods to decrease the need for vasopressors may enhance survival in AMICS.

Improved Outcomes Associated with the use of Shock Protocols: Updates from the National Cardiogenic Shock Initiative.

BACKGROUND: The National Cardiogenic Shock Initiative is a single-arm, prospective, multicenter study to assess outcomes associated with early mechanical circulatory support (MCS) in patients presenting with acute myocardial infarction and cardiogenic shock (AMICS) treated with percutaneous coronary intervention (PCI). METHODS: Between July 2016 and February 2019, 35 sites participated and enrolled into the study. All centers agreed to treat patients with AMICS using a standard protocol emphasizing invasive hemodynamic monitoring and rapid initiation of MCS. Inclusion and exclusion criteria mimicked those of the "SHOCK" trial with an additional exclusion criteria of intra-aortic balloon pump counter-pulsation prior to MCS. RESULTS: A total of 171 consecutive patients were enrolled. Patients had an average age of 63 years, 77% were male, and 68% were admitted with AMICS. About 83% of patients were on vasopressors or inotropes, 20% had a witnessed out of hospital cardiac arrest, 29% had in-hospital cardiac arrest, and 10% were under active cardiopulmonary resuscitation during MCS implantation. In accordance with the protocol, 74% of patients had MCS implanted prior to PCI. Right heart catheterization was performed in 92%. About 78% of patients presented with ST-elevation myocardial infarction with average door to support times of 85 ± 63 min and door to balloon times of 87 ± 58 min. Survival to discharge was 72%. Creatinine ≥2, lactate >4, cardiac power output (CPO) <0.6 W, and age ≥ 70 years were predictors of mortality. Lactate and CPO measurements at 12-24 hr reliably predicted overall mortality postindex procedure. CONCLUSION: In contemporary practice, use of a shock protocol emphasizing best practices is associated with improved outcomes.

Emerging therapeutic agents to lower lipoprotein (a) levels.

PURPOSE OF REVIEW: Recent epidemiological and genetic studies have suggested that lipoprotein (a) [Lp(a)] is a causal mediator of cardiovascular disease (CVD). There is now interest in evaluating Lp(a) as a therapeutic target. This review will summarize emerging therapeutic agents to lower Lp(a). RECENT FINDINGS: Apheresis is the most efficacious method to lower Lp(a). Currently, there are no approved drugs to specifically lower Lp(a). However, recent data has demonstrated that Lp(a) can be significantly lowered, along with reductions in other apolipoprotein B-100 (apoB) containing lipoproteins, with antisense oligonucleotides to apoB, monoclonal antibodies to proprotein convertase subtilisin/kexin type 9, cholesterol ester transfer protein inhibitors, and thyromimetics. The farnesoid X receptor/fibroblast growth factor axis and interleukin-6 also influence Lp(a) levels and may be targets of therapy. Finally, specific apolipoprotein (a) [apo(a)] inhibitors apo(a) have been developed and reduce apo(a) mRNA and protein levels up to 86% without significantly affecting other lipoproteins. SUMMARY: Lp(a) remains the last major lipoprotein disorder without any specific therapy. With the strong and accumulating data on its role as a causal risk factor for CVD, a rationale exists to develop novel agents to reduce Lp(a) and test the hypothesis that this will lead to reduced CVD events.

Sustained Mechanical Aspiration Thrombectomy for High Thrombus Burden Coronary Vessel Occlusion: The Multicenter CHEETAH Study.

BACKGROUND: Poor myocardial reperfusion due to distal embolization and microvascular obstruction after percutaneous coronary intervention is associated with increased risk of morbidity and mortality. Prior trials have not shown a clear benefit of routine manual aspiration thrombectomy. Sustained mechanical aspiration may mitigate this risk and improve outcomes. The objective of this study is to evaluate sustained mechanical aspiration thrombectomy before percutaneous coronary intervention in high thrombus burden acute coronary syndrome patients. METHODS: This prospective study evaluated the Indigo CAT RX Aspiration System (Penumbra Inc, Alameda CA) for sustained mechanical aspiration thrombectomy before percutaneous coronary intervention at 25 hospitals across the USA. Adults presenting within 12 hours of symptom onset with high thrombus burden and target lesion(s) located in a native coronary artery were eligible. The primary end point was a composite of cardiovascular death, recurrent myocardial infarction, cardiogenic shock, or new or worsening New York Heart Association class IV heart failure within 30 days. Secondary end points included Thrombolysis in Myocardial Infarction thrombus grade, Thrombolysis in Myocardial Infarction flow, myocardial blush grade, stroke, and device-related serious adverse events. RESULTS: From August 2019 through December 2020, a total of 400 patients were enrolled (mean age 60.4 years, 76.25% male). The primary composite end point rate was 3.60% (14/389 [95% CI, 2.0-6.0%]). Rate of stroke within 30 days was 0.77%. Final rates of Thrombolysis in Myocardial Infarction thrombus grade 0, Thrombolysis in Myocardial Infarction flow 3, and myocardial blush grade 3 were 99.50%, 97.50%, and 99.75%, respectively. No device-related serious adverse events occurred. CONCLUSIONS: Sustained mechanical aspiration before percutaneous coronary intervention in high thrombus burden acute coronary syndrome patients was safe and was associated with high rates of thrombus removal, flow restoration, and normal myocardial perfusion on final angiography.

Early Utilization of Mechanical Circulatory Support in Acute Myocardial Infarction Complicated by Cardiogenic Shock: The National Cardiogenic Shock Initiative.

BACKGROUND: Acute myocardial infarction complicated by cardiogenic shock (AMI-CS) is associated with significant morbidity and mortality. Mechanical circulatory support (MCS) devices increase systemic blood pressure and end organ perfusion while reducing cardiac filling pressures. METHODS AND RESULTS: The National Cardiogenic Shock Initiative (NCT03677180) is a single-arm, multicenter study. The purpose of this study was to assess the feasibility and effectiveness of utilizing early MCS with Impella in patients presenting with AMI-CS. The primary end point was in-hospital mortality. A total of 406 patients were enrolled at 80 sites between 2016 and 2020. Average age was 64±12 years, 24% were female, 17% had a witnessed out-of-hospital cardiac arrest, 27% had in-hospital cardiac arrest, and 9% were under active cardiopulmonary resuscitation during MCS implantation. Patients presented with a mean systolic blood pressure of 77.2±19.2 mm Hg, 85% of patients were on vasopressors or inotropes, mean lactate was 4.8±3.9 mmol/L and cardiac power output was 0.67±0.29 watts. At 24 hours, mean systolic blood pressure improved to 103.9±17.8 mm Hg, lactate to 2.7±2.8 mmol/L, and cardiac power output to 1.0±1.3 watts. Procedural survival, survival to discharge, survival to 30 days, and survival to 1 year were 99%, 71%, 68%, and 53%, respectively. CONCLUSIONS: Early use of MCS in AMI-CS is feasible across varying health care settings and resulted in improvements to early hemodynamics and perfusion. Survival rates to hospital discharge were high. Given the encouraging results from our analysis, randomized clinical trials are warranted to assess the role of utilizing early MCS, using a standardized, multidisciplinary approach.

Antiplatelet Therapy in Acute Myocardial Infarction and Cardiogenic Shock: Insights From the National Cardiogenic Shock Initiative.

BACKGROUND: Patients presenting with acute myocardial infarction complicated by cardiogenic shock (AMI-CS) are at high risk for impaired antiplatelet activity secondary to malabsorption, systemic hypoperfusion, hypothermia, need for mechanical ventilation, and high use of analgesics. The use of antiplatelet therapy in these high-risk patients is not well studied. METHODS: Using the National Cardiogenic Shock Initiative database, we analyzed patients who presented with AMI-CS at 60 hospitals from March 2018 to December 2020. All patients were treated using a standard shock protocol. Herein, the patterns of antiplatelet use are described. RESULTS: A total of 204 patients were included in the analysis, of which 174 (85.3%) presented with ST-segment elevation myocardial infarction (STEMI). The majority (84.3%) received antiplatelet therapy before percutaneous coronary intervention (PCI); of those who received antiplatelets, 77.9% received aspirin, 55.2% received an oral P2Y12 inhibitor, and 19.2% received intravenous (IV) antiplatelet therapy. Ticagrelor was the most common P2Y12 inhibitor administered (41.9%), followed by clopidogrel (12.2%) and prasugrel (1.2%). Only 18.6% of oral antiplatelet agents were crushed. Baseline characteristics of patients who received IV vs non-IV antiplatelet agents were similar. Thrombolysis in Myocardial Infarction (TIMI) 0 flow was present in 69.6% of patients before PCI and aspiration thrombectomy was performed in 24.5% of patients. The presence of STEMI, cardiac arrest, cardiopulmonary resuscitation, hypothermia, vasopressor use, elevated lactate levels, or number of vessels treated did not influence the use of IV antiplatelet agents. CONCLUSIONS: The use of crushed and IV antiplatelet agents in AMI-CS is low. Further studies are needed in this high-risk population to assess whether more potent antiplatelet inhibition will improve outcomes.

Acoustic Shock Waves to Modify Calcific Plaques - Intravascular Lithotripsy in the Peripheral Circulation.

Intravascular lithotripsy (IVL) is a new technique for treatment of severely calcified lesions that uses acoustic shockwaves in a balloon-based system to induce fracture in calcific plaque, facilitating luminal gain and vessel expansion. In this review, we provide a concise summary of the available data and clinical experience of IVL in various peripheral vascular beds, including facilitating vascular access for large-bore devices. We discuss the physics and mode of action of IVL in modifying calcified plaques, include several illustrative examples of utility of IVL in peripheral interventions, and discuss the future directions for adoption of the technique in peripheral interventions.

The dilated coronary sinus: utility of coronary sinus cross-sectional area and eccentricity index in differentiating right atrial pressure overload from persistent left superior vena cava.

BACKGROUND: Pulmonary hypertension and right atrial pressure overload (RAPO) cause dilation of the coronary sinus (CS). Persistent connection of the left superior vena cava (LSVC) to the CS is another cause of CS dilation. The purpose of this study was to evaluate the usefulness of coronary sinus cross-sectional area (CSA) and eccentricity index (EI) in differentiating persistent LSVC from right heart overload and RAPO in patients with dilated CS. METHODS: We identified 15 patients with a dilated CS by echocardiography. Offline analysis was used to measure CS-CSA and CS-EI at end-diastole in the parasternal long axis plane. EI was defined as B/A, where A is the widest diameter and major axis of the CS, and B is the diameter of the minor axis (perpendicular to and bisecting A at its midpoint). Persistent LSVC was confirmed by either computed tomography or injection of agitated saline in the left antecubital vein. RESULTS: CS-CSA was significantly larger in PLSVC group than in group with RAPO. Also, CS-EI was lower in PLSVC than in RAPO group (P = 0.0003). EI was the most sensitive and specific discriminator between patients with persistent LSVC vs. RAPO. CS-EI was <0.8 in all PLSVC patients and >0.8 in all RAPO patients (sensitivity and specificity = 100%). CONCLUSION: Patients with persistent LSVC have a significantly higher CS-CSA than those with elevated RA pressure. When dilated CS is present, a CS-EI <0.8 is 100% sensitive and specific for persistent LSVC. Thus, the CS-EI can be used in cases of dilated CS to diagnose the presence of persistent LSVC with a very high degree of certainty, and can help differentiate this congenital anomaly from RAPO.

Percutaneous Impella Mechanical Circulatory Support Delivery Using Intravascular Lithotripsy.

Intravascular lithotripsy (IVL) may be useful to deliver Impella devices in patients with peripheral arterial disease. Twelve patients were treated with peripheral IVL prior to Impella insertion. A total of 100% of patients underwent successful device implantation with no IVL complications. IVL can facilitate transfemoral access for Impella insertion. (Level of Difficulty: Advanced.).

Multivessel Versus Culprit-Vessel Percutaneous Coronary Intervention in Cardiogenic Shock.

OBJECTIVES: This study sought to compare outcomes of patients enrolled in the NCSI (National Cardiogenic Shock Initiative) trial who were treated using a revascularization strategy of percutaneous coronary intervention (PCI) of multivessel PCI (MV-PCI) versus culprit-vessel PCI (CV-PCI). BACKGROUND: In patients with multivessel disease who present with acute myocardial infarction and cardiogenic shock (AMICS), intervening on the nonculprit vessel is controversial. There are conflicting published reports and lack of evidence, particularly in patients treated with early mechanical circulatory support (MCS). METHODS: From July 2016 to December 2019, patients who presented with AMICS to 57 participating hospitals were included in this analysis. All patients were treated using a standard shock protocol emphasizing early MCS, revascularization, and invasive hemodynamic monitoring. Patients with multivessel coronary artery disease (MVCAD) were analyzed according to whether CV-PCI or MV-PCI was undertaken during the index procedure. RESULTS: Of 198 patients with MVCAD, 126 underwent MV-PCI (64%) and 72 underwent CV-PCI (36%). Demographics between the cohorts were similar with respect to age, sex, history of diabetes, prior PCI or coronary artery bypass grafting, and prior history of myocardial infarction. Patients who underwent MV-PCI had a trend toward more severe impairment of cardiac output and worse lactate clearance on presentation, and cardiac performance was significantly worse at 12 h. However, 24 h from PCI, the hemometabolic derangements were similar. Survival and rates of acute kidney injury were not significantly different between groups (69.8% MV-PCI vs. 65.3% CV-PCI; p = 0.51; and 29.9% vs. 34.2%; p = 0.64, respectively). CONCLUSIONS: In patients with MVCAD presenting with AMICS treated with early MCS, revascularization of nonculprit lesions was associated with similar hospital survival and acute kidney injury when compared with culprit-only PCI. Selective nonculprit PCI can be safety performed in AMICS in patients supported with mechanical circulatory support.

Echocardiographic assessment of the accuracy of computed tomography in the diagnosis of hemodynamically significant pericardial effusions.

BACKGROUND: Although Doppler echocardiography is the noninvasive test of choice for the diagnosis of hemodynamically significant pericardial effusion (HSPE), pericardial effusion is often first detected by computed tomography (CT). Few data are available, however, regarding the accuracy of CT in the diagnosis of cardiac tamponade. METHODS: We retrospectively identified 28 consecutive hospitalized patients with pericardial effusion who underwent both chest CT and echocardiography within 48 hours between 2001 and 2005. CT images were analyzed by experienced radiologists without knowledge of the echo results. Radiologic findings were evaluated with Doppler echocardiography. RESULTS: Of the 28 patients, 15 had HSPE by echo criteria. Right ventricular wall flattening and pericardial thickening on CT correlated with HSPE with a positive predictive value of 79% and 67%, respectively. Inferior vena cava diameter by CT was not a useful predictor of HSPE. CT was most accurate in diagnosing HSPE when the effusions were large (n = 6) and was 100% sensitive and specific in this group. Of the small- to moderate-sized effusions (n = 22), the sensitivity and specificity were 80% and 75%, respectively. CONCLUSIONS: CT findings of right ventricular wall flattening, pericardial thickening, and a large pericardial effusion significantly increase the likelihood of tamponade. In this study, the majority of patients diagnosed with HSPE by CT did indeed have tamponade by standard echo criteria. Although not a useful screening tool in the diagnosis of HSPE, CT is of some help, and abnormal results warrant more urgent clinical evaluation.