First-in-Man Percutaneous Transaxillary Artery Placement and Removal of the Impella 5.0 Mechanical Circulatory Support Device

We report on the fully percutaneous insertion and removal of the Impella 5.0 microaxial flow device via the axillary artery in a patient with cardiogenic shock and peripheral artery disease. Due to inadequate iliofemoral vasculature and desire for mobility, the axillary artery was felt to be the most appropriate access approach for temporary mechanical circulatory support. The procedure was well tolerated and the patient was supported for 17 days, at which time the device was safely removed in a fully percutaneous manner at the time of permanent left ventricular assist device placement. Percutaneous transaxillary placement of the Impella 5.0 device is a feasible support option in cardiogenic shock in patients with hostile iliofemoral disease.

Pass the Rock: calcium, the achilles heel of transcatheter valve replacement

Increasing annular calcification portends more adverse outcomes and worse hemodynamic results following percutaneous structural heart interventions. Though the Direct Flow prosthesis did not appear to have significantly different post-procedural gradients based on aortic valve calcium burden in a selected group of patients, the average residual gradients were relatively high in all cases and the presence of a paravalvular leak was more common with increasing valvular calcification. It is unclear how the Direct Flow prosthesis fits into the armamentarium of TAVR prostheses.

Effectiveness of Arterial Closure Devices for Preventing Complications With Percutaneous Coronary Intervention: An Instrumental Variable Analysis

BACKGROUND

Bleeding is associated with poor outcomes after percutaneous coronary intervention (PCI). Although arterial closure devices (ACDs) are widely used in clinical practice, whether they are effective in reducing bleeding complications during transfemoral PCI is uncertain. The objective of this study was to evaluate the effectiveness of ACDs for the prevention of vascular access site complications in patients undergoing transfemoral PCI using an instrumental variable approach.

METHODS AND RESULTS

We performed a retrospective analysis of the CathPCI Registry from 2009 to 2013 at 1470 sites across the United States. Variation in the proportion of ACDs used by each individual physician operator was used as an instrumental variable to address potential confounding. A 2-stage instrumental variable analysis was used as the primary approach. The main outcome measure was vascular access site complications, and nonaccess site bleeding was used as a falsification end point (negative control) to evaluate for potential confounding. A total of 1 053 155 ACDs were used during 2 056 585 PCIs during the study period. The vascular access site complication rate was 1.5%. In the instrumental variable analysis, the use of ACDs was associated with a 0.40% absolute risk reduction in vascular access site complications (95% confidence interval, 0.31-0.42; number needed to treat=250). Absolute differences in nonaccess site bleeding were negligible (risk difference, 0.04%; 95% confidence interval, 0.01-0.07), suggesting acceptable control of confounding in the comparison.

CONCLUSIONS

ACDs are associated with a modest reduction in major bleeding after PCI. The number needed to treat with ACDs to prevent 1 major bleeding event is high.

Surgical Versus Percutaneous Femoral Access for Delivery of Large-Bore Cardiovascular Devices (from the PARTNER Trial)

It is unclear if surgical exposure confers a risk advantage compared with a percutaneous approach for patients undergoing endovascular procedures requiring large-bore femoral artery access. From the randomized controlled Placement of Aortic Transcatheter Valve trials A and B and the continued access registries, a total of 1,416 patients received transfemoral transcatheter aortic valve replacement, of which 857 underwent surgical, and 559 underwent percutaneous access. Thirty-day rates of major vascular complications and quality of life scores were assessed. Propensity matching was used to adjust for unmeasured confounders. Overall, there were 116 major vascular complications (8.2%). Complication rates decreased dramatically during the study period. In unadjusted analysis, major vascular complications were significantly less common in the percutaneous access group (35 [6.3%] vs 81 [9.5%] p = 0.032). However, among 292 propensity-matched pairs, there was no difference in major vascular complications (22 [7.5%] vs 28 [9.6%], p = 0.37). Percutaneous access was associated with fewer total in-hospital vascular complications (46 [16%] vs 66 [23%], p = 0.036), shorter median procedural duration (97 interquartile range [IQR 68 to 166] vs 121 [IQR 78 to 194] minutes, p <0.0001), and median length of stay (4 [IQR 2 to 8] vs 6 [IQR 3 to 10] days, p <0.0001). There were no significant differences in quality of life scores at 30 days. Surgical access for large-bore femoral access does not appear to confer any advantages over percutaneous access and may be associated with more minor vascular complications.

Variability in Antithrombotic Therapy Regimens Peri-TAVR: A Single Academic Center Experience

Introduction

The aim of this study was to describe peri-procedural antithrombotic use in patients undergoing transcatheter aortic valve replacement (TAVR) at a single academic medical center.

Methods

Retrospective collection of antiplatelet and anticoagulant use during the index hospitalization for all patients undergoing TAVR at our institution from April 2009 through March 2014.

Results

Of a total of 255 patients undergoing the procedure, 132 (51%) had an indication for anticoagulation pre-TAVR and 92 (70% of those with an indication) were on treatment. On discharge, 106 patients (44% of total surviving to discharge, 73% of those surviving with an indication for anticoagulation) were treated with oral anticoagulation. Of these patients, 89 (84%) were discharged on aspirin and an oral anticoagulant without clopidogrel. Only 122 (51% of total patients) were discharged on the regimen of aspirin and clopidogrel alone.

Conclusion

Peri-procedural antithrombotic regimens vary greatly following TAVR. More than half of patients have an indication for anticoagulation following the procedure. Most patients at our institution who require anticoagulation are discharged on aspirin and an oral anticoagulant, though the optimal regimen requires further investigation.

Electronic supplementary material

The online version of this article (doi:10.1007/s40119-015-0050-2) contains supplementary material, which is available to authorized users.

Outcomes in Nonagenarians Undergoing Transcatheter Aortic Valve Replacement in the PARTNER-I Trial

BACKGROUND

This study describes short-term and mid-term outcomes of nonagenarian patients undergoing transfemoral or transapical transcatheter aortic valve replacement (TAVR) in the Placement of Aortic Transcatheter Valve (PARTNER)-I trial.

METHODS

From April 2007 to February 2012, 531 nonagenarians, mean age 93 ± 2.1 years, underwent TAVR with a balloon-expandable prosthesis in the PARTNER-I trial: 329 through transfemoral (TF-TAVR) and 202 transapical (TA-TAVR) access. Clinical events were adjudicated and echocardiographic results analyzed in a core laboratory. Quality of life (QoL) data were obtained up to 1 year post-TAVR. Time-varying all-cause mortality was referenced to that of an age-sex-race-matched US population.

RESULTS

For TF-TAVR, post-procedure 30-day stroke risk was 3.6%; major adverse events occurred in 35% of patients; 30-day paravalvular leak was greater than moderate in 1.4%; median post-procedure length of stay (LOS) was 5 days. Thirty-day mortality was 4.0% and 3-year mortality 48% (44% for the matched population). By 6 months, most QoL measures had stabilized at a level considerably better than baseline, with Kansas City Cardiomyopathy Questionnaire (KCCQ) 72 ± 21. For TA-TAVR, post-procedure 30-day stroke risk was 2.0%; major adverse events 32%; 30-day paravalvular leak was greater than moderate in 0.61%; and median post-procedure LOS was 8 days. Thirty-day mortality was 12% and 3-year mortality 54% (42% for the matched population); KCCQ was 73 ± 23.

CONCLUSIONS

A TAVR can be performed in nonagenarians with acceptable short- and mid-term outcomes. Although TF- and TA-TAVR outcomes are not directly comparable, TA-TAVR appears to carry a higher risk of early death without a difference in intermediate-term mortality. Age alone should not preclude referral for TAVR in nonagenarians.

Temporal Trends in Percutaneous Coronary Intervention Appropriateness: Insights From the Clinical Outcomes Assessment Program

BACKGROUND

It is unknown whether the appropriate use of percutaneous coronary intervention (PCI) has improved over time and whether trends in PCI appropriateness have been accompanied by changes in the use of PCI.

METHODS AND RESULTS

We applied appropriate use criteria to determine the appropriateness of all 51 872 PCI performed in Washington State from 2010 through 2013. We evaluated the number of PCIs performed from 2006 through 2013 to provide a comparator period that preceded statewide appropriateness assessment beginning in 2010. Between 2010 and 2013, the overall number of PCI decreased by 6.8% (13 267 PCIs in 2010 to 12 193 in 2013) with a 43% decline in the number of PCIs for elective indications (3818 PCIs in 2010 to 2193 PCIs in 2013). The decline in the use of elective PCI was significantly larger after the onset of statewide PCI appropriateness assessment in 2010 (P=0.03). The proportion of elective PCIs classified as appropriate increased from 26% in 2010 to 38% in 2013, whereas the proportion of inappropriate PCIs decreased from 16% to 13% (P<0.001 for trends). Significant improvements in the proportion of inappropriate PCI were limited to the tertile of hospitals with the largest decline in PCIs classified as inappropriate (25% in 2010 to 12% in 2013; P=0.03).

CONCLUSIONS

In Washington State, the use of PCI for elective indications has decreased over time with concurrent improvements in PCI appropriateness. However, improvements in PCI appropriateness were limited to a minority of hospitals. Understanding processes at these high-performing hospitals may inform efforts to improve PCI appropriateness.

Association between public reporting of outcomes with procedural management and mortality for patients with acute myocardial infarction

BACKGROUND

Public reporting of procedural outcomes may create disincentives to provide percutaneous coronary intervention (PCI) for critically ill patients.

OBJECTIVES

This study evaluated the association between public reporting with procedural management and outcomes among patients with acute myocardial infarction (AMI).

METHODS

Using the Nationwide Inpatient Sample, we identified all patients with a primary diagnosis of AMI in states with public reporting (Massachusetts and New York) and regionally comparable states without public reporting (Connecticut, Maine, Maryland, New Hampshire, Rhode Island, and Vermont) between 2005 and 2011. Procedural management and in-hospital outcomes were stratified by public reporting.

RESULTS

Among 84,121 patients hospitalized with AMI, 57,629 (69%) underwent treatment in a public reporting state. After multivariate adjustment, percutaneous revascularization was performed less often in public reporting states than in nonreporting states (odds ratio [OR]: 0.81, 95% confidence interval [CI]: 0.67 to 0.96), especially among older patients (OR: 0.75, 95% CI: 0.62 to 0.91), those with Medicare insurance (OR: 0.75, 95% CI: 0.62 to 0.91), and those presenting with ST-segment elevation myocardial infarction (OR: 0.63, 95% CI: 0.56 to 0.71) or concomitant cardiac arrest or cardiogenic shock (OR: 0.58, 95% CI: 0.47 to 0.70). Overall, patients with AMI in public reporting states had higher adjusted in-hospital mortality rates (OR: 1.21, 95% CI: 1.06 to 1.37) than those in nonreporting states. This was observed predominantly in patients who did not receive percutaneous revascularization in public reporting states (adjusted OR: 1.30, 95% CI: 1.13 to 1.50), whereas those undergoing the procedure had lower mortality (OR: 0.71, 95% CI: 0.62 to 0.83).

CONCLUSIONS

Public reporting is associated with reduced percutaneous revascularization and increased in-hospital mortality among patients with AMI, particularly among patients not selected for PCI.

Abstract 23: Temporal Trends in Percutaneous Coronary Intervention Appropriateness: Insights from the Clinical Outcomes Assessment Program

Background: It is unknown if the appropriate use of percutaneous coronary intervention (PCI) has improved over time and whether trends in PCI appropriateness have been accompanied by changes in the rate of PCI use.

Methods: We applied 2012 Appropriate Use Criteria to determine the appropriateness of all 51,872 PCI performed in Washington State from 2010 through 2013. PCI procedural rates were studied from 2006 through 2013 to provide a comparator period that preceded statewide appropriateness assessment beginning in 2010. Procedural appropriateness and rates of use were determined separately for acute (ST segment elevation myocardial infarction, non-ST segment myocardial infarction, unstable angina) and elective (stable angina) indications.

Results: Between 2010 and 2013, the overall rate of PCI decreased by 6.8% (13,267 PCI in 2010 to 12,193 in 2013) with a 43% decline in the rate of PCI for elective indications (3,818 PCI in 2010 to 2,193 PCI in 2013) (Figure). The rate of decline in elective PCI procedures was significantly larger following the onset of statewide PCI appropriateness assessment in 2010 (P = 0.03). The proportion of PCI for acute indications classified as appropriate remained >92% throughout the study period. The proportion of elective PCI classified as appropriate increased from 26% in 2010 to 38% in 2013 while the proportion of inappropriate PCI decreased from 16% to 13% (P<0.001 for trends) (Table). Improvements in the rate of inappropriate PCI were limited to the tertile of hospitals with the largest decline in PCI classified as inappropriate (25% in 2010 to 12% in 2013; P=0.03).

Conclusions: In Washington State, the use of PCI for non-acute indications has decreased over time with concurrent improvements in PCI appropriateness. However, improvements in PCI appropriateness were limited to a minority of hospitals. Understanding processes at these high-performing hospitals may inform efforts to improve PCI appropriateness.

Usefulness and safety of ultrasound-assisted catheter-directed thrombolysis for submassive pulmonary emboli

The optimal treatment for intermediate-risk pulmonary embolism (PE) remains unclear. Our goal was to describe the safety and efficacy of the EkoSonic ultrasound-assisted catheter-directed thrombolysis system (EKOS Corporation, Bothell, Washington) in a real-world registry of patients with intermediate-risk PE. Fifty-three consecutive patients with intermediate-risk PE treated with ultrasound-assisted catheter-directed thrombolysis at Brigham and Women's Hospital from 2010 to 2014 were analyzed. The primary outcome was a change in directly measured pulmonary artery pressures as assessed using logistic regression with generalized estimating equations to account for serial measurements. Patients received an average of 24.6 ± 9 mg of alteplase using the EKOS catheter with an average treatment time of 15.9 ± 3 hours. After treatment, there was a 7.2- and a 11.4-mm Hg reduction in mean and systolic pulmonary artery pressure (95% confidence interval 4.7 to 9.7 mm Hg, p <0.001, and 95% confidence interval 7.8 to 15.0 mm Hg, p <0.001), respectively. In this cohort, 9.4% had any bleeding complication noted during their hospital stay. One patient's alteplase was prematurely discontinued for access site bleeding although no other interventions were required related to bleeding complications.

Adoption of the hybrid CTO approach by a single non-CTO operator: procedural and clinical outcomes

BACKGROUND

The feasibility of adopting the "hybrid" approach by a single operator without prior experience in percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs) has not been described.

METHODS

Consecutive patients who underwent CTO-PCI by a single operator using the "hybrid" approach between 2012 and 2013 formed the analytic cohort. No patient was declined on the basis of angiographic findings. Clinical and angiographic characteristics together with procedural and hospital outcomes are described.

RESULTS

During the study period, a total of 48 consecutive patients underwent PCI of 50 CTOs. Mean age was 63.4 ± 9.4 years and most patients (83%) were men. The right coronary artery (RCA) was the most commonly treated CTO vessel (54%) and mean J-CTO score was 2.3 ± 1.1. A primary retrograde approach was chosen for 33% of lesions and 40% required use of an epicardial collateral vessel. The primary strategy was effective in 65% of successful cases, 35% required one change in strategy, and 15% requiring two strategy changes. Procedural success rate was 92%. The median number of stents used was 3 (interquartile range [IQR], 2-4] and the total stent length was 73 mm [IQR, 38-96 mm). Mean contrast volume was 356.4 ± 148.3 mL and the mean air kerma radiation exposure was 3.5 ± 2.0 Gy. No patient experienced a major periprocedural complication.

CONCLUSION

The "hybrid" approach to CTO-PCI can be successfully adopted by a single operator with excellent early procedural success and low complication rates, despite a lack of prior CTO-PCI experience.

Procedural failure of chronic total occlusion percutaneous coronary intervention: Insights from a multicenter US registry

BACKGROUND

The hybrid approach to chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has significantly increased procedural success rates, yet some cases still fail. We sought to evaluate the causes of failure in a contemporary CTO PCI registry.

METHODS

We examined 380 consecutive patients who underwent CTO-PCI at 4 high volume CTO PCI centers in the United States using the "hybrid" approach. Clinical, angiographic, complication, and efficiency outcomes were compared between successful and failed cases. Failed cases were individually reviewed by an independent reviewer to determine the cause of failure.

RESULTS

Procedural success was 91.3%. Compared with patients in whom CTO PCI was successful, those in whom CTO PCI failed had similar baseline clinical characteristics, but were more likely to have longer occlusion length, more tortuosity, more proximal cap ambiguity and blunt stump, and higher mean J-CTO scores (2.8 ± 1.1 vs. 3.5 ± 1.0, P < 0.001), and less likely to have collaterals suitable for the retrograde approach (66% vs. 45%, P = 0.021). Failure was due to a complication in 10 cases (30%). In the remaining 23 cases (70%) failure was due to inability to wire the lesion (n = 21, 4 of which were CTOs due to in-stent restenosis), or poor antegrade flow after PCI (n = 5).

CONCLUSIONS

Compared with successful cases, failed CTO-PCI cases are more likely to have higher J-CTO scores, longer occlusion length, ambiguous proximal cap and no appropriate collaterals for retrograde crossing. Development of novel CTO crossing techniques is needed to further increase CTO PCI success rates.

Defining unavoidable delays in primary percutaneous coronary intervention: discordance among patients excluded from National Cardiovascular Quality Registries

Background

The Centers for Medicaid and Medicare Services (CMS) and the National Cardiovascular Data Registry (NCDR) track primary percutaneous coronary intervention (PCI) performance in the form of door‐to‐balloon time. For quality assessment, exceptions are made for patients with “unavoidable delays” in both registries, yet it remains unclear how consistently such patients are identified.

Methods and Results

All primary PCI patients at 3 Massachusetts hospitals (Brigham and Women's, Massachusetts General, and North Shore Medical Center) from 2009 to 2011 were evaluated for CMS inclusion/exclusion and NCDR nonsystems delay (NSD) status. We subsequently analyzed patient characteristics and outcomes based on these strata. Among 456 total patients, 128 (28%) were excluded from CMS reporting, whereas 56 (12%) were listed in the NCDR registry as having an NSD. Forty of 56 (71%) patients with NSD were also excluded from CMS reporting, whereas 312 of 400 (78%) patients reported without NSD were included in CMS reports. Between‐registry agreement on patients with unavoidable delays was modest (κ=0.32). Among CMS‐included patients without NSD, 94% received PCI within 90 minutes compared with 29% of CMS‐excluded patients with NSD (P<0.001). Likewise, CMS‐included patients without NSD had a 4‐fold better 1‐year mortality rate compared with CMS‐excluded patients with NSD (P<0.001).

Conclusions

More than twice as many primary PCI patients are excluded from CMS quality analyses compared with NCDR. With the use of currently available cardiovascular quality registries, it is unclear how many patients truly require unavoidable delays during primary PCI. Patients with NSD had the worst outcomes regardless of CMS status.

Impact of public reporting and outlier status identification on percutaneous coronary intervention case selection in Massachusetts

OBJECTIVES

This study sought to evaluate the impact of public reporting of hospitals as negative outliers on percutaneous coronary intervention (PCI) case-mix selection.

BACKGROUND

Public reporting of risk-adjusted in-hospital mortality after PCI is intended to improve outcomes. However, public labeling of negative outliers based on risk-adjusted mortality rates may detrimentally affect hospitals' willingness to care for high-risk patients.

METHODS

We used generalized estimating equations to examine expected in-hospital mortality rates for 116,227 PCI patients at all nonfederally funded Massachusetts hospitals performing PCI from 2003 to 2010. The main outcome measure was the change in predicted in-hospital mortality rates per hospital after outlier status identification.

RESULTS

The prevalence-weighted mean expected mortality for all PCI cases during the study period was 1.38 ± 0.36% (5.3 ± 1.96% for all shock or ST-segment elevation myocardial infarction patients, 0.58 ± 0.19% for all not shock, not ST-segment elevation myocardial infarction patients). After public identification as a negative outlier institution, there was an 18% relative reduction (absolute 0.25% reduction) in predicted mortality among PCI patients at outlier institutions (95% confidence interval: -0.04 to -0.46%, p = 0.021) compared with nonoutlier institutions. Throughout the study period, there was an additional 37% relative (0.51% absolute) reduction in the predicted mortality risk among all PCI patients in Massachusetts attributable to secular changes since the onset of public reporting (95% confidence interval: -0.20 to -0.83, p = 0.002).

CONCLUSIONS

The risk profile of PCI patients at outlier institutions was significantly lower after public identification compared with nonoutlier institutions, suggesting that risk-aversive behaviors among PCI operators at outlier institutions may be an unintended consequence of public reporting in Massachusetts.

Reporting trends and outcomes in ST-segment-elevation myocardial infarction national hospital quality assessment programs

BACKGROUND

For patients who undergo primary percutaneous coronary intervention (PCI) for ST-segment-elevation myocardial infarction, the door-to-balloon time is an important performance measure reported to the Centers for Medicare & Medicaid Services (CMS) and tied to hospital quality assessment and reimbursement. We sought to assess the use and impact of exclusion criteria associated with the CMS measure of door-to-balloon time in primary PCI.

METHODS AND RESULTS

All primary PCI-eligible patients at 3 Massachusetts hospitals (Brigham and Women's, Massachusetts General, and North Shore Medical Center) were evaluated for CMS reporting status. Rates of CMS reporting exclusion were the primary end points of interest. Key secondary end points were between-group differences in patient characteristics, door-to-balloon times, and 1-year mortality rates. From 2005 to 2011, 26% (408) of the 1548 primary PCI cases were excluded from CMS reporting. This percentage increased over the study period from 13.9% in 2005 to 36.7% in the first 3 quarters of 2011 (P<0.001). The most frequent cause of exclusion was for a diagnostic dilemma such as a nondiagnostic initial ECG, accounting for 31.2% of excluded patients. Although 95% of CMS-reported cases met door-to-balloon time goals in 2011, this was true of only 61% of CMS-excluded cases and consequently 82.6% of all primary PCI cases performed that year. The 1-year mortality for CMS-excluded patients was double that of CMS-included patients (13.5% versus 6.6%; P<0.001).

CONCLUSIONS

More than a quarter of patients who underwent primary PCI were excluded from hospital quality reports collected by CMS, and this percentage has grown substantially over time. These findings may have significant implications for our understanding of process improvement in primary PCI and mechanisms for reimbursement through Medicare.

Incidence and implications of idiopathic thrombocytopenia following transcatheter aortic valve replacement with the Edwards Sapien(©) valves: a single center experience

OBJECTIVES

To determine the incidence and etiology of thrombocytopenia following transcatheter Aortic valve replacement (TAVR).

BACKGROUND

the use of TAVR in the United States has grown rapidly. Anecdotally, thrombocytopenia following TAVR with the Sapien valves has been observed, though little is known about this phenomenon.

METHODS

All patients treated with TAVR using a Sapien valve or who underwent isolated balloon aortic valvuloplasty (BAV) at Brigham and Women's Hospital from October 2009 through November 2012 were analyzed. Post-procedure thrombocytopenia severity was stratified as none (>150,000 cells/μL), mild (100-150,000), and moderate to severe (<100,000). Summary statistics and simple comparisons were evaluated. Linear regression models were used to identify patient or procedural factors associated with platelet count nadir.

RESULTS

112 TAVR and 105 BAV patients were analyzed. Following TAVR the prevalence of thrombocytopenia was 69% and the incidence of new thrombocytopenia was 45% compared to 37% and 17% respectively following BAV (P < 0.01). Similar results were found across all strata of thrombocytopenia severity. Post-TAVR platelet nadirs were greater by 1,840 cells/μL for each 1% increase in STS score (P = 0.03) and 670 cells/μL greater for each 1 mmHg increase in pre-TAVR mean aortic stenosis gradient. Among TAVR patients, thrombocytopenia appears to spontaneously resolve an average of 8 days post-procedure. No differences in clinical outcomes based on thrombocytopenia severity were observed except for an increased use of blood products (P = 0.05).

CONCLUSIONS

Thrombocytopenia following TAVR with the Edwards' Sapien valves is a frequent but generally self-limited process. The etiology of this phenomenon is unknown.

Physician accuracy in interpreting potential ST-segment elevation myocardial infarction electrocardiograms

Background

With adoption of telemedicine, physicians are increasingly asked to diagnose ST‐segment elevation myocardial infarctions (STEMIs) based on electrocardiograms (ECGs) with minimal associated clinical information. We sought to determine physicians' diagnostic agreement and accuracy when interpreting potential STEMI ECGs.

Methods and Results

A cross‐sectional survey was performed consisting of 36 deidentified ECGs that had previously resulted in putative STEMI diagnoses. Emergency physicians, cardiologists, and interventional cardiologists participated in the survey. For each ECG, physicians were asked, “based on the ECG above, is there a blocked coronary artery present causing a STEMI?” The reference standard for ascertaining the STEMI diagnosis was subsequent emergent coronary arteriography. Responses were analyzed with generalized estimating equations to account for nested and repeated measures. One hundred twenty‐four physicians interpreted a total of 4392 ECGs. Among all physicians, interreader agreement (kappa) for ECG interpretation was 0.33, reflecting poor agreement. The sensitivity to identify “true” STEMIs was 65% (95% CI: 63 to 67) and the specificity was 79% (95% CI: 77 to 81). There was a 6% increase in the odds of accurate ECG interpretation for every 5 years of experience since medical school graduation (OR 1.06, 95% CI: 1.02 to 1.10, P=0.01). After adjusting for experience, there was no significant difference in the odds of accurate interpretation by specialty—Emergency Medicine (reference), General Cardiology (AOR 0.97, 95% CI: 0.79 to 1.2, P=0.80), or Interventional Cardiology physicians (AOR 1.24, 95% CI: 0.93 to 1.7, P=0.15).

Conclusions

There is significant physician disagreement in interpreting ECGs with features concerning for STEMI. Such ECGs lack the necessary sensitivity and specificity to act as a suitable “stand‐alone” diagnostic test.

Clinical characteristics and reperfusion times among patients with an isolated posterior myocardial infarction

BACKGROUND

An isolated posterior myocardial infarction (PMI) is associated with significant morbidity and mortality. Because physicians often fail to recognize this diagnosis, there may be delays in the timely revascularization of these patients. The present study sought to identify the clinical characteristics and reperfusion times among patients presenting with isolated PMI.

METHODS

We identified subjects with isolated PMI within a registry of all catheterization laboratory activations for ST-elevation myocardial infarction (STEMI) from 2008 to 2012. Association between PMI and revascularization within 90 minutes was evaluated by logistic regression.

RESULTS

Among 318 patients who underwent revascularization for STEMI, a total of 20 (6%) had electrocardiographic evidence of an isolated PMI. Compared to non-PMI STEMI, subjects with PMI were more often female (45% vs 22%; P=.02) and less likely to have chest pain (40% vs 75%; P<.01). The median door-to-activation (25.5 min vs 12 min; P<.01), activation-to-laboratory (36.5 min vs 29 min; P<.01) and door-to-balloon times (107 min vs 72 min; P<.01) were longer among subjects with PMI, with fewer patients achieving reperfusion within 90 minutes (30% vs 71%; P<.01). After multivariable adjustment, individuals with PMI had 82% lower odds (adjusted odds ratio, 0.18; 95% confidence interval, 0.06-0.50) of achieving coronary reperfusion within 90 minutes. Door-to-activation time accounted for 96% of variation in the total revascularization time (R²=0.96; P<.0001).

CONCLUSIONS

Door-to-activation time was prolonged for those with PMI, resulting in longer door-to-balloon times and fewer patients revascularized within the recommended time. An isolated PMI should be considered among individuals presenting with symptoms consistent with myocardial infarction.

Comparison of clinical characteristics and outcomes of cardiac arrest survivors having versus not having coronary angiography

Prompt percutaneous coronary intervention is associated with improved survival in patients presenting with cardiac arrest. Few studies, however, have focused on patients with cardiac arrest not selected for coronary angiography. The aim of the present study was to evaluate the clinical characteristics and outcomes of patients with cardiac arrest denied emergent angiography. Patients with cardiac arrest were identified within a registry that included all catheterization laboratory activations from 2008 to 2012. Logistic regression and proportional-hazards models were created to assess the clinical characteristics and mortality associated with denying emergent angiography. Among 664 patients referred for catheterization, 110 (17%) had cardiac arrest, and 26 of these patients did not undergo emergent angiography. Most subjects (69%) were turned down for angiography for clinical reasons and a minority for perceived futility (27%). After multivariate adjustment, pulseless electrical activity as the initial arrest rhythm (adjusted odds ratio [AOR] 13.27, 95% confidence interval [CI] 1.76 to 100.12), <1.0 mm of ST-segment elevation (AOR 10.26, 95% CI 1.68 to 62.73), female gender (AOR 4.45, 95% CI 1.04 to 19.08), and advancing age (AOR 1.10 per year, 95% CI 1.04 to 1.16) were associated with increased odds of withholding angiography. The mortality rate was markedly higher for patients who were denied emergent angiography (hazard ratio 3.64, 95% CI 2.05 to 6.49), even after adjustment for medical acuity (hazard ratio 2.29, 95% CI 1.19 to 4.41). In conclusion, older subjects, women, and patients without ST-segment elevation were more commonly denied emergent angiography after cardiac arrest. Patients denied emergent angiography had increased mortality that persisted after adjustment for illness severity.

Electrocardiographic criteria for ST-elevation myocardial infarction in patients with left ventricular hypertrophy

Patients with electrocardiographic (ECG) left ventricular hypertrophy (LVH) have repolarization abnormalities of the ST segment that may be confused with an ischemic current of injury. We analyzed the ACTIVATE-SF database, a registry of consecutive emergency department ST-segment elevation (STE) myocardial infarction diagnoses from 2 medical centers. Univariate analysis was performed to identify ECG variables associated with presence of an angiographic culprit lesion. Recursive partitioning was then applied to identify a clinical decision-making rule that maximizes sensitivity and specificity for presence of an angiographic culprit lesion. Seventy-nine patients with ECG LVH underwent emergency cardiac catheterization for primary angioplasty. Patients with a culprit lesion had greater magnitude of STE (3.0 ± 1.8 vs 1.9 ± 1.0 mm, p = 0.005), more leads with STE (3.1 ± 1.6 vs 2.0 ± 1.8 leads, p = 0.002), and a greater ratio of STE to R-S-wave magnitude (median 25% vs 9.2%, p = 0.003). Univariate application of ECG criteria had limited sensitivity and a high false-positive rate for identifying patients with an angiographic culprit lesion. In patients with anterior territory STE, using a ratio of ST segment to R-S-wave magnitude ≥25% as a diagnostic criteria for STE myocardial infarction significantly improved specificity for an angiographic culprit lesion without decreasing sensitivity (c-statistic 0.82), with a net reclassification improvement of 37%. In conclusion, application of an ST segment to R-S-wave magnitude ≥25% rule may augment current criteria for determining which patients with ECG LVH should undergo primary angioplasty.

Delaying primary percutaneous coronary intervention for computed tomographic scans in the emergency department

Patients presenting with suspected ST-segment elevation myocardial infarction (STEMI) may have important alternative diagnoses (e.g., aortic dissection, pulmonary emboli) or safety concerns for STEMI management (e.g., head trauma). Computed tomographic (CT) scanning may help in identifying these alternative diagnoses but may also needlessly delay primary percutaneous coronary intervention (PCI). We analyzed the ACTIVATE-SF Registry, which consists of consecutive patients with a clinical diagnosis of STEMI admitted to the emergency departments of 2 urban hospitals. Of 410 patients with a suspected diagnosis of STEMI, 45 (11%) underwent CT scanning before primary PCI. Presenting electrocardiograms, baseline risk factors, and presence of an angiographic culprit vessel were similar in those with and without CT scanning before PCI. Only 2 (4%) of these CT scans changed clinical management by identifying a stroke. Patients who underwent CT scanning had far longer door-to-balloon times (median 166 vs 75 minutes, p <0.001) and higher in-hospital mortality (20% vs 7.8%, p = 0.006). After multivariate adjustment, CT scanning in the emergency department before primary PCI remained independently associated with longer door-to-balloon times (100% longer, 95% confidence interval 60 to 160, p <0.001) but was no longer associated with mortality (odds ratio 1.4, p = 0.5). In conclusion, CT scanning before primary PCI rarely changed management and was associated with significant delays in door-to-balloon times. More judicious use of CT scanning should be considered.