Positron emission tomography myocardial perfusion imaging (PET MPI) findings predictive of post-liver transplant major adverse cardiac events.

Positron emission tomography myocardial perfusion imaging (PET MPI) is a noninvasive diagnostic test capable of detecting coronary artery disease, structural heart disease, and myocardial flow reserve (MFR). We aimed to determine the prognostic utility of PET MPI to predict post-liver transplant (LT) major adverse cardiac events (MACE). Among the 215 LT candidates that completed PET MPI between 2015 and 2020, 84 underwent LT and had 4 biomarker variables of clinical interest on pre-LT PET MPI (summed stress and difference scores, resting left ventricular ejection fraction, global MFR). Post-LT MACE were defined as acute coronary syndrome, heart failure, sustained arrhythmia, or cardiac arrest within the first 12 months post-LT. Cox regression models were constructed to determine associations between PET MPI variable/s and post-LT MACE. The median LT recipient age was 58 years, 71% were male, 49% had NAFLD, 63% reported prior smoking, 51% had hypertension, and 38% had diabetes mellitus. A total of 20 MACE occurred in 16 patients (19%) at a median of 61.5 days post-LT. One-year survival of MACE patients was significantly lower than those without MACE (54% vs. 98%, p =0.001). On multivariate analysis, reduced global MFR ≤1.38 was associated with a higher risk of MACE [HR=3.42 (1.23-9.47), p =0.019], and every % reduction in left ventricular ejection fraction was associated with an 8.6% higher risk of MACE [HR=0.92 (0.86-0.98), p =0.012]. Nearly 20% of LT recipients experienced MACE within the first 12 months of LT. Reduced global MFR and reduced resting left ventricular ejection fraction on PET MPI among LT candidates were associated with increased risk of post-LT MACE. Awareness of these PET-MPI parameters may help improve cardiac risk stratification of LT candidates if confirmed in future studies.

The initial U.S. experience with the Tempo active fixation temporary pacing lead in structural heart interventions.

OBJECTIVES: This multicenter retrospective study of the initial U.S. experience evaluated the safety and efficacy of temporary cardiac pacing with the Tempo® Temporary Pacing Lead. BACKGROUND: Despite increasing use of temporary cardiac pacing with the rapid growth of structural heart procedures, temporary pacing leads have not significantly improved. The Tempo lead is a new temporary pacing lead with a soft tip intended to minimize the risk of perforation and a novel active fixation mechanism designed to enhance lead stability. METHODS: Data from 269 consecutive structural heart procedures were collected. Outcomes included device safety (absence of clinically significant cardiac perforation, new pericardial effusion, or sustained ventricular arrhythmia) and efficacy (clinically acceptable pacing thresholds with successful pace capture throughout the index procedure). Postprocedure practices and sustained lead performance were also analyzed. RESULTS: The Tempo lead was successfully positioned in the right ventricle and achieved pacing in 264 of 269 patients (98.1%). Two patients (0.8%) experienced loss of pace capture. Procedural mean pace capture threshold (PCT) was 0.7 ± 0.8 mA. There were no clinically significant perforations, pericardial effusions, or sustained device-related arrhythmias. The Tempo lead was left in place postprocedure in 189 patients (71.6%) for mean duration of 43.3 ± 0.7 hr (range 2.5-221.3 hr) with final PCT of 0.84 ± 1.04 mA (n = 80). Of these patients, 84.1% mobilized out of bed with no lead dislodgment. CONCLUSION: The Tempo lead is safe and effective for temporary cardiac pacing for structural heart procedures, provides stable peri and postprocedural pacing and allows mobilization of patients who require temporary pacing leads.

Atrioventricular conduction in patients undergoing pacemaker implant following self-expandable transcatheter aortic valve replacement.

BACKGROUND: Heart block requiring a pacemaker is common after self-expandable transcatheter aortic valve replacement (SE-TAVR); however, conduction abnormalities may improve over time. Optimal device management in these patients is unknown. OBJECTIVE: To evaluate the long-term, natural history of conduction disturbances in patients undergoing pacemaker implantation following SE-TAVR. METHODS: All patients who underwent new cardiac implantable electronic device (CIED) implantation at Michigan Medicine following SE-TAVR placement between January 1, 2012 and September 25, 2017 were identified. Electrocardiogram and device interrogation data were examined during follow-up to identify patients with recovery of conduction. Logistic regression analysis was used to compare clinical and procedural variables to predict conduction recovery. RESULTS: Following SE-TAVR, 17.5% of patients underwent device placement for new atrioventricular (AV) block. Among 40 patients with an average follow-up time of 17.1 ± 8.1 months, 20 (50%) patients had durable recovery of AV conduction. Among 20 patients without long-term recovery, four (20%) had transient recovery. The time to transient conduction recovery was 2.2 ± 0.2 months with repeat loss of conduction at 8.2 ± 0.9 months. On multivariate analysis, larger aortic annular size (odds ratio: 0.53 [0.28-0.86]/mm, P = 0.02) predicted lack of conduction recovery. CONCLUSIONS: Half of the patients undergoing CIED placement for heart block following SE-TAVR recovered AV conduction within several months and maintained this over an extended follow-up period. Some patients demonstrated transient recovery of conduction before recurrence of conduction loss. Larger aortic annulus diameter was negatively associated with conduction recovery.

Door-to-balloon time and mortality among patients undergoing primary PCI.

BACKGROUND: Current guidelines for the treatment of ST-segment elevation myocardial infarction recommend a door-to-balloon time of 90 minutes or less for patients undergoing primary percutaneous coronary intervention (PCI). Door-to-balloon time has become a performance measure and is the focus of regional and national quality-improvement initiatives. However, it is not known whether national improvements in door-to-balloon times have been accompanied by a decline in mortality. METHODS: We analyzed annual trends in door-to-balloon times and in-hospital mortality using data from 96,738 admissions for patients undergoing primary PCI for ST-segment elevation myocardial infarction from July 2005 through June 2009 at 515 hospitals participating in the CathPCI Registry. In a subgroup analysis using a linked Medicare data set, we assessed 30-day mortality. RESULTS: Median door-to-balloon times declined significantly, from 83 minutes in the 12 months from July 2005 through June 2006 to 67 minutes in the 12 months from July 2008 through June 2009 (P<0.001). Similarly, the percentage of patients for whom the door-to-balloon time was 90 minutes or less increased from 59.7% in the first year to 83.1% in the last year (P<0.001). Despite improvements in door-to-balloon times, there was no significant overall change in unadjusted in-hospital mortality (4.8% in 2005-2006 and 4.7% in 2008-2009, P=0.43 for trend) or in risk-adjusted in-hospital mortality (5.0% in 2005-2006 and 4.7% in 2008-2009, P=0.34), nor was a significant difference observed in unadjusted 30-day mortality (P=0.64). CONCLUSIONS: Although national door-to-balloon times have improved significantly for patients undergoing primary PCI for ST-segment elevation myocardial infarction, in-hospital mortality has remained virtually unchanged. These data suggest that additional strategies are needed to reduce in-hospital mortality in this population. (Funded by the National Cardiovascular Data Registry of the American College of Cardiology Foundation.).

Contemporary Trends and Outcomes of Intravascular Lithotripsy in Percutaneous Coronary Intervention: Insights From BMC2.

BACKGROUND: With an aging population and an increase in the comorbidity burden of patients undergoing percutaneous coronary intervention (PCI), the management of coronary calcification for optimal PCI is critical in contemporary practice. OBJECTIVES: This study sought to examine the trends and outcomes of coronary intravascular lithotripsy (IVL), rotational/orbital atherectomy, or both among patients who underwent PCI in Michigan. METHODS: We included all PCIs between January 1, 2021, and June 30, 2022, performed at 48 Michigan hospitals. Outcomes included in-hospital major adverse cardiac events (MACEs) and procedural success. RESULTS: IVL was used in 1,090 patients (2.57%), atherectomy was used in 1,743 (4.10%) patients, and both were used in 240 patients (0.57% of all PCIs). IVL use increased from 0.04% of PCI cases in January 2021 to 4.28% of cases in June 2022, ultimately exceeding the rate of atherectomy use. The rate of MACEs (4.3% vs 5.4%; P = 0.23) and procedural success (89.4% vs 89.1%; P = 0.88) were similar among patients treated with IVL compared with atherectomy, respectively. Only 15.6% of patients treated with IVL in contemporary practice were similar to the population enrolled in the pivotal IVL trials. Among such patients (n = 169), the rate of MACEs (0.0%) and procedural success (94.7%) were similar to the outcomes reported in the pivotal IVL trials. CONCLUSIONS: Since its introduction in February 2021, coronary IVL use has steadily increased, exceeding atherectomy use in Michigan by February 2022. Contemporary use of IVL and atherectomy is generally associated with high rates of procedural success and low rates of complications.

Transcatheter Aortic Valve Replacement for Left Ventricular Assist Device-Related Aortic Regurgitation: The Michigan Medicine Experience.

Background: Aortic regurgitation (AR) is common and detrimental in patients with left ventricular assist devices (LVADs). Off-label use of transcatheter aortic valve replacement (TAVR) has emerged as a potential treatment option. Further data are required regarding the feasibility and outcomes of TAVR to treat AR in LVAD recipients. Methods: A retrospective review of all patients with LVADs who underwent TAVR for the treatment of AR at a single center was performed. All echocardiograms were independently reviewed to ensure accuracy. Results: Eleven patients with continuous-flow LVADs underwent TAVR for AR. All patients had moderate or severe AR with New York Heart Association (NYHA) class III and IV symptoms. Implantation of more than 1 valve was required in 4 (36.3%) patients; 1 patient died during the procedure because of valve migration into the left ventricle and 1 patient died in-hospital after TAVR. Of 9 (81.8%) patients discharged alive, 8 (72.7%) were alive at 12 months and all survivors had improvement in AR severity, natriuretic peptide levels, left ventricle end-diastolic diameter, and NYHA class. Five (62.5%) survivors had a large improvement (>20 points) in the Kansas City Cardiomyopathy Questionnaire score at 1 year. One survivor experienced heart failure, requiring hospitalization, within 1 year. Conclusions: In this single-center series, TAVR for the treatment of AR in patients with LVADs is technically challenging but feasible in select patients and may produce durable improvements in AR severity, functional status, and quality of life.

Acute ST-elevation myocardial infarction.

PURPOSE OF REVIEW: Acute ST-elevation myocardial infarction (STEMI) is a major cause of morbidity, mortality, and disability. This review summarizes recent advances in the treatment of patients with STEMI. RECENT FINDINGS: The best prehospital and interhospital transfer strategy for patients with STEMI is rapid transport to a percutaneous coronary intervention (PCI) center by Emergency Medical Services, with prehospital diagnosis and activation of the cardiac catheterization laboratory. Coronary angiography is now recommended for all patients with STEMI. Advances in adjunctive pharmacological and device therapy have improved primary PCI results. Thrombus aspiration, drug-eluting stents, systemic hypothermia for survivors of cardiac arrest with anoxic encephalopathy, and stem cells as reparative therapy have undergone recent evaluation. SUMMARY: Primary PCI with stent implantation as soon as possible is the best treatment strategy for patients with STEMI. Aspirin, bivalirudin, and either prasugrel or ticagrelor are the best antithrombotic agents to support primary PCI. Thrombus aspiration and intra-aortic balloon counterpulsation are important device adjuncts. Systemic hypothermia appears to be an important advance for survivors of cardiac arrest with anoxic encephalopathy, but the benefits of stem cell therapy have yet to be proven.

Predicting Contrast-Induced Renal Complications.

Chronic kidney disease is a major risk factor for developing coronary artery disease, serving as an independent risk factor while overlapping with other risk factors. Percutaneous coronary intervention is a cornerstone of therapy for coronary artery disease and requires contrast media, which can contribute to renal injury. Identifying patients at risk for contrast-induced nephropathy is critical for preventing renal injury, which is associated with short- and long-term mortality. Determination of the potential risk for contrast-induced nephropathy and a new need for dialysis using validated risk prediction tools is a method of identifying patients at high risk for this complication.

Percutaneous Coronary Intervention for Chronic Total Occlusion-The Michigan Experience: Insights From the BMC2 Registry.

OBJECTIVES: The aim of this study was to describe the performance and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in Michigan. BACKGROUND: CTO PCI has been associated with reduction in angina, but previous registry analyses showed a higher rate of major adverse cardiac events with this procedure. METHODS: To study uptake and outcomes of CTO PCI in Michigan, patients enrolled in the BMC2 (Blue Cross Blue Shield of Michigan Cardiovascular Consortium) registry (2010 to 2017) were evaluated. CTO PCI was defined as intervention in a 100% occluded coronary artery ≥3 months old. RESULTS: Among 210,172 patients enrolled in the registry, 7,389 CTO PCIs (3.5%) were attempted, with 4,614 (58.3%) achieving post-procedural TIMI (Thrombolysis In Myocardial Infarction) flow grade 3. The proportion of PCIs performed on CTOs increased over the study period (from 2.67% in 2010 to 4.48% in 2017). Thirty of 47 hospitals performed >50 CTO interventions in 2017. Pre-procedural angina class ≤2 was present in one-quarter, and functional assessment for ischemia was performed in 46.6% of patients. Major complications occurred in 245 patients (3.3%) and included death (1.4%), post-procedural stroke (0.4%), cardiac tamponade (0.5%), and urgent coronary artery bypass graft surgery (1.3%). Procedural success improved modestly from 44.5% in 2010 to 54.9% in 2017 (p for trend < 0.001). Rates of in-hospital mortality (p for trend = 0.247) and major adverse cardiac event (p for trend = 0.859) for CTO PCI remained unchanged over the study period. CONCLUSIONS: The rate of CTO PCI in Michigan increased over the study period. Although the success rate of CTO PCI has increased modestly in contemporary practice, it remained far below the >80% reported by select high-volume CTO operators. The rate of periprocedural major adverse cardiac events or death remained unchanged over time. These data suggest room for improvement in the selection and functional assessment of CTO lesions before subjecting patients to the increased procedural risk associated with CTO PCI.

Association of Operator and Hospital Experience With Procedural Success Rates and Outcomes in Patients Undergoing Percutaneous Coronary Interventions for Chronic Total Occlusions: Insights From the Blue Cross Blue Shield of Michigan Cardiovascular Consortium.

BACKGROUND: An inverse relationship has been described between procedural success and outcomes of all major cardiovascular procedures. However, this relationship has not been studied for percutaneous coronary intervention (PCI) of chronic total occlusion (CTO). METHODS: We analyzed the data on patients enrolled in Blue Cross Blue Shield of Michigan Cardiovascular Consortium registry in Michigan (January 1, 2010 to March 31, 2018) to evaluate the association of operator and hospital experience with procedural success and outcomes of patients undergoing CTO-PCI. CTO-PCI was defined as intervention of a 100% occluded coronary artery presumed to be ≥3 months old. RESULTS: Among 210 172 patients enrolled in the registry, 7389 (3.5%) CTO-PCIs were attempted with a success rate of 53%. CTO-PCI success increased with operator experience (45% and 65% in the lowest and highest experience tertiles) and was the highest for highly experienced operators at higher experience centers and the lowest for inexperienced operators at low experience hospitals. Multivariable logistic regression models (with spline transformed prior operator and institutional experience) demonstrated a positive relationship between prior operator and site experience and procedural success rates (likelihood ratio test=141.12, df=15, P<0.001) but no relationship between operator and site experience and major adverse cardiac event (likelihood ratio test=19.12, df=15, P=0.208). CONCLUSIONS: Operator and hospital CTO-PCI experiences were directly related to procedural success but were not related to major adverse cardiac event among patients undergoing CTO-PCIs. Inexperienced operators at high experience centers had significantly higher success but not major adverse cardiac event rates compared with inexperienced operators at low experience centers. These data suggested that CTO-PCI safety and success could potentially be improved by selective referral of these procedures to experienced operators working at highly experienced centers.

Root Cause Analysis of Deaths in ST-Segment Elevation Myocardial Infarctions Treated With Primary PCI: What Can We Do Better?

OBJECTIVE: Recent data demonstrate that mortality of patients with ST-elevation myocardial infarction (STEMI) has not changed despite dramatic reduction in door-to-balloon times. Identifying potential areas in care that can be further optimized to decrease mortality remains a priority. METHODS: We performed a root cause analysis of all patients who died following primary percutaneous coronary intervention (PCI) during index hospitalization from 2008 to 2013 at the University of Michigan. Using a standardized data collection form, two interventional cardiologists and one non-invasive cardiologist reviewed patient care prior to arrival to the catheterization lab, while in the catheterization lab, and after primary PCI to determine cause of death and to rate potential preventability of death on a Likert scale (0 unpreventable - 4 mostly preventable). RESULTS: Of the 25 deaths over the 5-year period, 8 were deemed at least mildly preventable by one or more reviewer. No death was deemed totally preventable. Interreviewer agreement was moderate for both cause of death (nominal Krippendorff's alpha = .58) and preventability of death (nominal alpha = .233). In spite of this overall lack of agreement, in all 8 preventable cases at least one reviewer cited ischemia to balloon time as a potentially addressable factor associated with the death. CONCLUSION: Mortality following primary PCI was deemed mostly unpreventable. However, improvement in total ischemic time, and in particular symptom-onset to medical care, was identified as one potential target that might be of value in further reducing the mortality associated with STEMI.

Mortality Predictors in Patients Referred for but Not Undergoing Transcatheter Aortic Valve Replacement.

Although transcatheter aortic valve replacement (TAVR) has expanded the proportion of patients with aortic stenosis (AS) who are candidates for valve replacement, some patients remain untreated, and their outcomes are not clear. We evaluated 172 consecutive patients with severe symptomatic AS referred for TAVR who declined (n = 55) or were not candidates for (n = 117) intervention. We examined clinical and echocardiographic variables associated with mortality. There were 77 deaths, and mean follow-up was 17.9 ± 10.9 months for survivors. Mortality rate at 1 and 2 years was 39.2% and 52.6%, respectively. There was a significant difference in mortality rate between patients who declined the procedure and those who were not candidates (p = 0.001), with 1-year mortality rates of 20.6% and 48.4%, respectively. On multivariate analysis, 4 variables were independently associated with all-cause mortality: New York Heart Association Class IV heart failure (hazard ratio [HR] 2.6, 95% confidence interval [CI] 1.6 to 4.2, p <0.001), glomerular filtration rate <48 ml/min (HR 2.1, 95% CI 1.3 to 3.4, p = 0.002), albumin <3.9 g/dl (HR 1.9, 95% CI 1.2 to 3.1, p = 0.007), and ejection fraction <50% (HR 1.9, 95% CI 1.4 to 3.0, p = 0.01). In this new era with expanded treatment options, patients with severe symptomatic AS who remain untreated after referral for TAVR experience a mortality rate of 39% at 1 year. The presence of advanced heart failure, renal dysfunction, low albumin, and/or left ventricular dysfunction identifies patients at higher risk of mortality.

Cause and circumstance of in-hospital mortality among patients undergoing contemporary percutaneous coronary intervention: a root-cause analysis.

BACKGROUND: Prior studies suggest that most deaths in patients undergoing percutaneous coronary intervention (PCI) are related to procedural complications. Mortality associated with PCI has steadily declined during the past decade, and the cause and circumstance of death among patients undergoing PCI in the contemporary era remain unknown. METHODS AND RESULTS: We evaluated all patients undergoing PCI at the University of Michigan from 2001 to 2009. There were 85 deaths among a total of 5520 patients undergoing PCI during this time period. By using a standardized data collection form, 3 cardiologists (2 interventional, H.S.G. and D.S.M.; 1 noninvasive, A.M.B.) determined the cause and circumstance of death, in addition to grading the preventability of death. Left ventricular failure was the most common cause of death (35.3%, n=30), followed by neurological compromise (16.5%, n=14) and arrhythmia (12.1%, n=12). The circumstance of death was mostly acute cardiac (52.9%, n=45), with a procedural complication composing a small fraction (7.1%, n=6). Reviewers determined 93% of deaths to be mostly or entirely unpreventable. CONCLUSIONS: Procedural complications are responsible for a small fraction of deaths among patients undergoing contemporary PCI. Measures to further enhance procedural safety are unlikely to translate into meaningful reductions in PCI mortality.

Symptomatic carotid artery stenosis: what is the preferred treatment?

Stroke is a major cause of mortality, morbidity, and disability. Carotid artery disease is the etiology for 15% to 20% of stroke. Carotid endarterectomy (CEA) reduces the risk of ipsilateral stroke and death in symptomatic patients with 50% to 99% carotid artery stenosis when the operative risk of stroke or death is less than 6%. Treatment benefit is greater with earlier surgery, more severe stenoses, and older age. Recently, carotid artery stenting (CAS) has emerged as a treatment option, especially in patients with high surgical risk due to anatomic or clinical variables. Nondisabling stroke risk may be higher with CAS than CEA, but the difference is narrowed with the use of embolic protection devices. The risk for myocardial infarction is lower with CAS than CEA. There is no difference in risk for disabling stroke or death. Worse results with new or low-volume CAS operators is a concern. CEA and CAS are complementary revascularization strategies. CEA may be preferred in older patients with complex anatomy or bulky plaques. CAS may be preferred in younger patients and those with restenosis, history of neck radiation, surgical contraindications, or surgically inaccessible lesions. The role for optimal medical therapy as an alternative treatment strategy remains to be defined. Nevertheless, all patients should be treated with lifestyle interventions and secondary risk factor control to target levels to reduce the risk of subsequent atherosclerotic events.

Evaluation of patients with suspected coronary artery disease.

Coronary artery disease affects millions of Americans and is a major cause of global morbidity and mortality. Detection and optimal treatment strategies are needed to reduce the clinical and economic burden of this disease. Chest pain history, risk factor profile, and noninvasive stress test results are used for clinical risk stratification. In high-risk patients, coronary angiography is the standard for anatomic diagnosis and additional risk stratification. All patients with coronary artery disease should be treated with optimal medical therapy. Patients with uncontrolled symptoms or high risk for adverse outcomes benefit from coronary artery revascularization with percutaneous coronary intervention or coronary artery bypass graft surgery.