Management of Myocardial Infarction: Emerging Paradigms for the Future.

Despite significant advancements in managing acute ST-segment elevation myocardial infarctions, the prevalence of heart failure has not decreased. Emerging paradigms with a focus on reducing infarct size show promising evidence in the improvement of the incidence of heart failure after experiencing acute coronary syndromes. Limiting infarct size has been the focus of multiple clinical trials over the past decades and has led to left ventricular (LV) unloading as a potential mechanism. Contemporary use of microaxial flow devices for LV unloading has suggested improvement in mortality in acute myocardial infarction complicated by cardiogenic shock. This review focuses on clinical data demonstrating evidence of infarct size reduction and highlights ongoing clinical trials that provide a new therapeutic approach to the management of acute myocardial infarction.

Derivation and validation of Pd/Pa in the assessment of residual ischemia post-intervention: A prospective all-comer registry.

BACKGROUND: Measurement of post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR) demonstrates residual ischemia in a large percentage of cases deemed angiographically successful which, in turn, has been associated with worse long-term outcomes. It has recently been shown that a resting pressure index, Pd/Pa, has prognostic value post stenting, however, its diagnostic value relative to FFR post-PCI has not been evaluated. METHODS: The diagnostic accuracy of Pd/Pa in identifying ischemia (FFR≤0.80) pre- and post-PCI was evaluated. Three patient subsets were analyzed. A reference pre-PCI cohort of 1,255 patients (1,560 vessels) was used to measure the accuracy of pre-PCI Pd/Pa vs. FFR. A derivation post-PCI group of 574 patient (664 vessels) was then used to calculate the diagnostic accuracy of post-PCI Pd/Pa vs. FFR. A final prospective validation cohort of 230 patients (255 vessels) was used to test and validate the diagnostic performance of post-PCI Pd/Pa. RESULTS: Median Pd/Pa and FFR were 0.90 (IQR 0.90-0.98) and 0.80 (IQR 0.71-0.88) in the reference pre-PCI model, 0.96 (IQR 0.93-1.00) and 0.87 (IQR 0.77-0.90) in the post-PCI derivation model, and 0.94 (IQR 0.89-0.97) and 0.84 (IQR 0.77-0.90) in the post-PCI validation model respectively. There was a strong linear correlation between Pd/Pa and FFR in all three models (p < 0.0001). Using ROC analysis, the optimal Pd/Pa cutoff value to predict a FFR ≤ 0.80 was ≤0.92 (AUC 0.87) in the pre-PCI model, ≤0.93 (AUC 0.85) in the post-PCI derivation model, and ≤ 0.90 (AUC 0.91) in the post-PCI validation model. Using a hybrid strategy of post-PCI Pd/Pa and post-PCI FFR when necessary (25% patients), overall diagnostic accuracy was improved to 95%. CONCLUSIONS: Pd/Pa has excellent diagnostic accuracy for identifying ischemia post-intervention. Using a hybrid strategy of post-PCI Pd/Pa first, and FFR afterwards, if required, adenosine administration can be avoided in over 75% of physiologic assessments post intervention.

Orbital Atherectomy for Treatment of Severely Calcified Coronary Artery Bifurcation Lesions: A Multicenter Analysis.

OBJECTIVE: This study evaluated the safety and efficacy of orbital atherectomy (OA) for the treatment of severely calcified coronary artery bifurcation lesions. BACKGROUND: Percutaneous coronary intervention (PCI) of severely calcified coronary artery lesions is associated with lower procedural success and higher rates of target lesion failure compared to non-calcified lesions. OA is an effective treatment for calcified coronary artery lesions prior to stent implantation. However, there is little data regarding the safety and efficacy of OA in patients with coronary artery bifurcation lesions. METHODS: Data were obtained from analysis of patients with severe coronary artery calcification who underwent OA and coronary stent implantation at ten high-volume institutions. Data were pooled and analyzed to assess peri-procedural outcomes and 30-day major adverse cardiac events (MACE). RESULTS: A total of 1156 patients were treated with OA and PCI. 363 lesions were at a coronary artery bifurcation. There were no statistically significant differences in baseline characteristics between the bifurcation and non-bifurcation groups. In the bifurcation group, treatment involved the left anterior descending artery and its branches more frequently and right coronary artery less frequently. After propensity score matching, the 30-day freedom from MACE was not statistically significant between the two groups. CONCLUSION: In this multicenter cohort analysis, patients with severely calcified coronary bifurcation lesions had low rates of MACE and target vessel revascularization at 30 days at rates comparable to non-bifurcation lesions. This analysis demonstrates that OA is safe and effective for complex coronary lesions at both bifurcation and non-bifurcation locations.

Surge in Delayed Myocardial Infarction Presentations: An Inadvertent Consequence of Social Distancing During the COVID-19 Pandemic.

This case series summarizes our experience of delayed acute myocardial infarction presentations during the coronavirus disease-2019 pandemic predominantly driven by patient fear of contracting the virus in the hospital. Many presented with complications rarely seen in the primary percutaneous coronary intervention era including ventricular septal rupture, left ventricular pseudoaneurysm, and right ventricular infarction. (Level of Difficulty: Beginner.).

Lower Extremity Revascularization Using Optical Coherence Tomography-Guided Directional Atherectomy: Final Results of the EValuatIon of the PantheriS OptIcal COherence Tomography ImagiNg Atherectomy System for Use in the Peripheral Vasculature (VISION) Study.

PURPOSE: To evaluate the safety and efficacy of a novel optical coherence tomography (OCT)-guided atherectomy catheter in treating patients with symptomatic femoropopliteal disease. METHODS: The VISION trial ( ClinicalTrials.gov identifier NCT01937351) was a single-arm, multicenter, global investigational device exemption study enrolling 158 subjects (mean age 67.2±10.5 years; 87 men) across 20 participating sites. In this cohort, 198 lesions were treated with an average length of 53±40 mm using the Pantheris catheter alone or Pantheris + adjunctive therapy. The primary safety endpoint was the composite of major adverse events (MAEs) through 6 months (objective performance goal 43.2%). Technical success (primary efficacy outcome) was defined as the percent of target lesions with a residual diameter stenosis ≤50% after treatment with the Pantheris device alone (objective performance goal 87.0%). Procedural success was defined as reduction in stenosis to ≤30% after Pantheris ± adjunctive therapy. Tissue specimens retrieved from each treated lesion were histologically analyzed to evaluate the accuracy and precision of OCT image guidance. RESULTS: The primary efficacy outcome was achieved in 192 (97.0%) of the 198 lesions treated with the Pantheris catheter. Across all lesions, mean diameter stenosis was reduced from 78.7%±15.1% at baseline to 30.3%±11.8% after Pantheris alone (p<0.001) and to 22.4%±9.9% after Pantheris ± adjunctive therapy (p<0.001). Of the 198 target lesions, 104 (52.5%) were treated with the Pantheris alone, 84 (42.4%) were treated with Pantheris + adjunctive angioplasty, and 10 (5.1%) with Pantheris + angioplasty + stenting. The composite MAE outcome through 6 months occurred in 25 (16.6%) of 151 subjects. There were no clinically significant perforations, 1 (0.5%) catheter-related dissection, 4 (2%) embolic events, and a 6.4% clinically driven target lesion revascularization rate at 6 months. The 40-lesion chronic total occlusion (CTO) subset (mean lesion length 82±38 mm) achieved a similar significant reduction in stenosis to 35.5%±13.6% after Pantheris alone (p<0.001). Histological analysis of atherectomy specimens confirmed <1% adventitia in 82.1% of the samples, highlighting the precision of OCT guidance. Characterization of the OCT-guided lesions revealed evidence of an underestimation of disease burden when using fluoroscopy. CONCLUSION: OCT-guided atherectomy for femoropopliteal disease is safe and effective. Additionally, the precision afforded by OCT guidance leads to greater removal of plaque during atherectomy while sparing the adventitia.

Hypertension in African Americans with heart failure: progression from hypertrophy to dilatation; perhaps not.

AIM: Concentric hypertrophy is thought to transition to left ventricular (LV) dilatation and systolic failure in the presence of long standing hypertension (HTN). Whether or not this transition routinely occurs in humans is unknown. METHODS: We consecutively enrolled African American patients hospitalized for acute decompensated volume overload heart failure (HF) in this retrospective study. All patients had a history of HTN and absence of obstructive coronary disease. Patients were divided into those with normal left ventricular ejection fraction (LVEF) and reduced LVEF. LV dimensions were measured according to standard ASE recommendations. LV mass was calculated using the ASE formula with Devereux correction. RESULTS: Patients with normal LVEF HF were significantly older, female and had a longer duration of HTN with higher systolic blood pressure on admission. LV wall thickness was similarly elevated in both groups. LV mass was elevated in both groups however was significantly greater in the reduced LVEF HF group compared to the normal LVEF HF group. Furthermore, gender was an independent predictor for LV wall thickness in normal LVEF HF group. CONCLUSION: In African American patients with HF our study questions the paradigm that concentric hypertrophy transitions to LV dilatation and systolic failure in the presence of HTN. Genetics and gender likely play a role in an individual's response to long standing hypertension.

Feasibility of the 3D RCA catheter to engage the brachiocephalic vessels during carotid angiography and stenting.

BACKGROUND: Engagement of the brachiocephalic vessels during carotid angiography is performed using a JR-4, Vitek, or other catheters with variable success. These catheters require additional training for safe manipulation. In this study, we evaluated the feasibility of using the 3D RCA catheter which requires less manipulation in the aorta, and less training, to engage the brachiocephalic vessels. METHODS: We prospectively studied consecutive high-risk patients undergoing carotid angiography and stenting from August 2005 to March 2009 at our institution. A baseline aortogram was performed to define the arch type in all patients. Engagement of the brachiocephalic vessels was initially attempted using the 3D RCA catheter using the following approach: The 3D RCA catheter is positioned in the ascending aorta beyond the brachiocephalic vessels take off. The natural curve of the catheter usually makes it point cephalad spontaneously in most patients and as it is gently withdrawn it engages the aortic arch vessels without much manipulation. Clinical follow-up with a neurological exam was performed at one month and six months. RESULTS: A total of 52 patients were enrolled in this study. Baseline demographics and aortic arch types encountered are listed in Table I. The 3D RCA catheter readily engaged the brachiocephalic vessels in 50/52 patients (96.0 %) in our cohort of patients undergoing carotid angiography. Of the 52 patients, 43 subsequently underwent carotid stenting and shuttle sheath placement was facilitated by initial engagement of the relevant common carotid artery with the 3D RCA catheter. There was one transient neurologic complication that resolved by 5 days in a patient that underwent carotid stenting. CONCLUSIONS: The 3D RCA catheter can be used with a high success rate to engage the brachiocephalic vessels in all 3 arch types, including a bovine arch during carotid angiography and facilitates shuttle sheath placement for carotid stenting. It requires less manipulation and therefore may be a more operator friendly approach. © 2010 Wiley-Liss, Inc.

Determinants of right ventricular failure in patients admitted with acute left heart failure.

Pulmonary hypertension, which may lead to right ventricular (RV) failure, increases with left ventricular (LV) diastolic dysfunction severity. The prevalence and determinants of RV failure were analyzed in 120 patients admitted with acute left heart (LH) failure. Patients were divided into RV failure (n=50) and non-RV failure (n=70) groups. The prevalence of RV failure was found to be 42%. In both groups, two thirds of the patients had isolated LV diastolic dysfunction and the rest had combined LV systolic and diastolic dysfunction. Patients in the RV failure group were characterized by higher LV diastolic grade (2.2 ± 0.6 vs 1.84 ± 0.7; P=.0070), pulmonary artery systolic pressure (PASP; 57.8 ± 15.3 vs 50.14 ± 12.1 mm Hg; P=.0028), right atrial enlargement (92% vs 25.7%; P=.000001), and more-than-moderate tricuspid regurgitation (58% vs 27.1%; P=.0006). RV failure is a frequent finding in patients with advanced LH failure. It is strongly associated with the severity of LV diastolic dysfunction and the severity of PASP.

The use of midodrine in patients with advanced heart failure.

In many patients, the treatment of heart failure (HF) cannot be optimized because of pre-existing or treatment-induced hypotension. Midodrine, a peripheral alpha1-adrenergic agonist may allow for up-titration of neurohormonal antagonist therapy leading to improved outcomes. Ten consecutive patients with HF due to systolic dysfunction and symptomatic hypotension interfering with optimal medical therapy were started on midodrine. After a 6-month follow-up, a higher percentage of patients were on optimal HF therapy (angiotensin-converting enzyme inhibitor/angiotensin receptor blocker mg % of optimal dose 20% vs 57.5%; P<.001) (beta-blockers mg % optimal dose 37.5% vs 75%; P<.001) (spironolactone/eplerenone mg % 43.7% vs 95%; P<.001). This led to an improvement in left ventricular ejection fraction (baseline 24+/-9.4 vs 32.2+/-9.9; P<.001) and clinical outcomes, with a significant reduction in total hospital admissions (32 vs 12; P=.02) and total hospital days (150 vs 58; P=.02).

Cardiac amyloidosis in a patient with multiple myeloma: a case report and review of literature.

We report a case of a 52-year-old man with multiple myeloma and rapidly progressive heart failure who died unexpectedly from a probable arrhythmia. Postmortem examination revealed infiltrative amyloid cardiomyopathy, a rare cause of predominantly diastolic myocardial disease. Cardiac amyloidosis should be considered in any patient presenting with congestive heart failure, preserved systolic function, and a discrepancy between a low QRS voltage on electrocardiography and an apparent left ventricular hypertrophy on sonogram. The pattern of left ventricular diastolic dysfunction changes during the course of amyloidosis and the classically described restrictive physiology occurs only in advanced stages of the disease.

Right ventricular failure in patients with preserved ejection fraction and diastolic dysfunction: an underrecognized clinical entity.

It is well recognized that patients with severe left ventricular (LV) systolic dysfunction develop pulmonary venous hypertension or postcapillary pulmonary hypertension, which leads to an increase in pulmonary vascular resistance (PVR) and right ventricular (RV) systolic failure. It is often underrecognized, however, that patients with heart failure with preserved LV ejection fraction and diastolic dysfunction may also develop postcapillary pulmonary hypertension with elevated PVR leading to RV systolic failure. This form of biventricular failure is a result of diastolic failure on the left in patients with preserved LV ejection fraction and systolic failure on the right. At this time, there are no randomized trials or guidelines addressing the management of patients with diastolic heart failure with and without resultant RV failure. The authors review the pathophysiology, clinical presentation, and suggested treatment of this underrecognized clinical entity.

A functional clotting assay to monitor the hirudin dosage.

Hirudin, a direct thrombin inhibitor, has potential advantages over indirect thrombin inhibitors and is increasingly used in clinical settings. There are, however, large variations in individual responses to this drug and no recognized clinical laboratory tests used to monitor its anticoagulant effects. We evaluated the use of the thromboelastograph, a common clinical coagulation instrument, to monitor the effects of hirudin in vitro. We developed a novel, whole blood clotting assay that utilizes the tissue factor stimulating properties of mercuric ion to measure the anticoagulant potential of therapeutic doses of hirudin. At doses equivalent to those found in the therapeutic range, the thromboelastograph was capable of showing significant changes when compared with control and different concentrations of hirudin (P < 0.05). A linear relationship was observed between increasing concentrations of recombinant hirudin and clotting times. In conclusion, the use of this test system warrants further investigation for monitoring hirudin.

A comparison of nesiritide vs. epoprostenol in a patient with precapillary pulmonary hypertension due to scleroderma complicated by postcapillary pulmonary hypertension.

To the best of our knowledge, acute decompensated left-sided heart failure with preserved left ventricular ejection fraction in a patient with scleroderma has not been previously reported. We describe a patient with severe pulmonary hypertension due to limited scleroderma in whom nesiritide led to marked reductions in pulmonary arterial and capillary wedge pressure as well as resolution of symptoms and pulmonary edema. Subsequent epoprostenol use was associated with an increase in pulmonary capillary wedge pressure and a recurrence of pulmonary edema. Thus, nesiritide may be the preferred agent in scleroderma patients with severe pulmonary hypertension and preserved left ventricular systolic function since epoprostenol may lead to adverse hemodynamic effects.

Fatal ascending aorta-to-right ventricle fistula formation after Staphylococcus aureus endocarditis of bicuspid aortic valve.

We present a case of a 46-year-old man with advanced acquired immunodeficiency syndrome and congenitally bicuspid aortic valve endocarditis caused by methicillin- and gentamicin-resistant Staphylococcus aureus. Endocarditis led to root abscess formation, a complete heart block, and fistulous tract formation between the ascending aorta and the right ventricle. Although perivalvular abscess is not an unusual complication of native valve endocarditis, a fatal fistulous communication between the ascending aorta and the right ventricle is exceedingly rare.

Mitral bioprosthetic valve endocarditis caused by an unusual microorganism, Gemella morbillorum, in an intravenous drug user.

We report a case of Gemella morbillorum mitral bioprosthetic valve endocarditis with perivalvular extension in a 44-year-old human immunodeficiency virus-positive man who is an active intravenous drug user together with review of all published cases. This is only the second reported case of Gemella morbillorum endocarditis in a patient with a prosthetic valve.