How to assess nonresponsiveness to vasodilator stress

Myocardial perfusion imaging (MPI) is a powerful tool for the functional assessment of ischemia in patients with suspected or known coronary artery disease (CAD). Given that the diagnostic accuracy and prognostic value of MPI and post-test management are highly dependent on achieving an adequate stress vasodilatory response, it is critical to identify those who may not have adequately responded to vasodilator pharmacological stress agents such as adenosine, dipyridamole, and regadenoson. Caffeine, a potent inhibitor of the adenosine receptor, is a compound that can affect vasodilatory hemodynamics, result in false negative studies, and potentially alter management in cases of inaccurate test results. Vasodilator non-responsiveness can be suspected by examining hemodynamics, quantitative positron emission tomography (PET) metrics such as myocardial flow reserve (MFR), and splenic response to stress. Quantitative MFR values of 1-1.2 should raise suspicion for nonresponsiveness in the setting of normal perfusion, along with the absence of a splenic switch off. Newer metrics, such as splenic response ratio, can be used to aid in the identification of potential nonresponders to pharmacologic vasodilators.

Prevalence and Prognostic Importance of Abnormal Positron Emission Tomography Among Asymptomatic Patients With Diabetes Mellitus

BACKGROUND

Ischemia and reduced global myocardial blood flow reserve (MBFR) are associated with high cardiovascular risk among symptomatic patients with diabetes mellitus (DM).

OBJECTIVES

This study aimed to assess the prevalence and prognostic importance of silent ischemia and reduced MBFR among asymptomatic patients with DM.

METHODS

This study included 2,730 consecutive patients with DM, without known coronary artery disease (CAD) or cardiomyopathy, who underwent rubidium-82 rest/stress positron emission tomography (PET) myocardial perfusion imaging (MPI) from 2010 to 2016. These patients were followed up for all-cause mortality (n = 461) for a median follow-up of 3 years. Patients were considered asymptomatic if neither chest pain nor dyspnea was elicited. Rates of ischemia, reduced MBFR, and coronary microvascular dysfunction on PET were assessed in both groups. Cox regression was used to define the independent association of abnormal MPI markers with mortality.

RESULTS

One-quarter of patients with DM (23.7%; n = 647) were asymptomatic; ischemia was present in 30.5% (n = 197), reduced MBFR in 62.3% (n = 361), and coronary microvascular dysfunction in 32.7% (n = 200). In adjusted analyses, reduced MBFR (HR per 0.1 unit decrease in MBFR: 1.08 [95% CI: 1.03-1.12]; P = 0.001) and reduced ejection fraction (HR per 5% decrease: 1.10 [95% CI: 1.01-1.18]; P = 0.02) were independently prognostic of mortality among asymptomatic patients, but ischemia was not. This was comparable to DM patients with symptoms. Insulin use and older age were significant predictors of reduced MBFR among asymptomatic patients with DM.

CONCLUSIONS

In both symptomatic and asymptomatic patients with DM, impairment in MBFR is common and associated with greater mortality risk.

Influenza A (H1N1) Virus Outbreak in the Districts of Chhattisgarh: A Cross-Sectional Study

Background The H1N1 flu is a subtype of the influenza A virus, also known as the swine flu. An entirely new strain of the H1N1 virus started sickening people in the 2009-2010 flu season. It was a novel influenza virus combination that can infect humans, pigs, and birds. It was frequently referred to as the "swine flu." The virus may be able to spread for a little while longer in children and individuals with compromised immune systems. Objective The objective is to investigate the outbreaks of H1N1 among young adults in the Bastar District of Chhattisgarh. Methods Collection of the blood samples of 342 individuals between December 2015 and November 2017 was done. Thirty-one cases of Influenza A (H1N1) PDM09 virus infection were identified and confirmed. The molecular relationship between viruses is identified by the real-time polymerase chain reaction (RT-PCR) method. Result The majority of samples (n=13) were sourced from Raipur Medical College, followed by contributions from Durg District Hospital (n=5), Raigarh Medical College (n=4), Rajnandgaon District Hospital (n=3), Jagdalpur Medical College (n=2), Bilaspur Medical College (n=2), and smaller contributions from Dhamtari District Hospital and Gariyabandh Primary Health Care. Among these, 31 samples tested positive for Influenza A (H1N1) PDM 2009 virus, with a slightly higher prevalence among 19 female patients. Age-wise distribution revealed higher proportions of positive cases in the age groups of 0-10 years, 31-40 years, and 21-30 years. In the molecular analysis, 154 samples showed no target amplification, while 125 samples exhibited amplification of only Influenza A without subtype (H1) amplification. Remarkably, 31 patients who tested positive for Influenza A (H1N1) died from the virus; most of the deaths were in children under five and middle-aged adults. Conclusion The detection of Influenza A (H1N1) PDM 2009 virus, especially among females, indicates its persistent circulation. Positive cases were prevalent among younger and middle-aged individuals. Molecular analysis showed subtype variations, with significant fatalities observed in children under five and middle-aged adults, emphasizing the severity of the virus across different age groups. It is advised that in order to keep Indian influenza surveillance up to date and robust, more epidemiological data should be gathered, along with information on risk factors like immunization status, hospitalization, and mortality rates should be estimated, and influenza case subtyping should be improved.

Analyzing Surgical Technique in Diverse Open Surgical Videos With Multitask Machine Learning

Objective

To overcome limitations of open surgery artificial intelligence (AI) models by curating the largest collection of annotated videos and to leverage this AI-ready data set to develop a generalizable multitask AI model capable of real-time understanding of clinically significant surgical behaviors in prospectively collected real-world surgical videos.

Design, Setting, and Participants

The study team programmatically queried open surgery procedures on YouTube and manually annotated selected videos to create the AI-ready data set used to train a multitask AI model for 2 proof-of-concept studies, one generating surgical signatures that define the patterns of a given procedure and the other identifying kinematics of hand motion that correlate with surgeon skill level and experience. The Annotated Videos of Open Surgery (AVOS) data set includes 1997 videos from 23 open-surgical procedure types uploaded to YouTube from 50 countries over the last 15 years. Prospectively recorded surgical videos were collected from a single tertiary care academic medical center. Deidentified videos were recorded of surgeons performing open surgical procedures and analyzed for correlation with surgical training.

Exposures

The multitask AI model was trained on the AI-ready video data set and then retrospectively applied to the prospectively collected video data set.

Main Outcomes and Measures

Analysis of open surgical videos in near real-time, performance on AI-ready and prospectively collected videos, and quantification of surgeon skill.

Results

Using the AI-ready data set, the study team developed a multitask AI model capable of real-time understanding of surgical behaviors-the building blocks of procedural flow and surgeon skill-across space and time. Through principal component analysis, a single compound skill feature was identified, composed of a linear combination of kinematic hand attributes. This feature was a significant discriminator between experienced surgeons and surgical trainees across 101 prospectively collected surgical videos of 14 operators. For each unit increase in the compound feature value, the odds of the operator being an experienced surgeon were 3.6 times higher (95% CI, 1.67-7.62; P = .001).

Conclusions and Relevance

In this observational study, the AVOS-trained model was applied to analyze prospectively collected open surgical videos and identify kinematic descriptors of surgical skill related to efficiency of hand motion. The ability to provide AI-deduced insights into surgical structure and skill is valuable in optimizing surgical skill acquisition and ultimately improving surgical care.

Accurate and efficient rapid acquisition early post-injection stress-first CZT SPECT myocardial perfusion imaging with tetrofosmin and attenuation correction

INTRODUCTION

Myocardial perfusion imaging (MPI) protocols have not changed significantly despite advances in instrumentation and software. We compared an early post-injection, stress-first SPECT protocol to standard delayed imaging.

METHODS

95 patients referred for SPECT MPI were imaged upright and supine on a Spectrum Dynamics D-SPECT CZT system with CT attenuation correction. Patients received injection of 99mTc tetrofosmin at peak of regadenoson stress and were imaged. Early post-stress (mean 17 ± 2 minutes) and Standard 1-h delay (mean 61 ± 13 min). Three blinded readers evaluated images for overall interpretation, perceived need for rest imaging, image quality, and reader confidence. Laboratory efficiency was also evaluated.

RESULTS

Blinded readers had the same response for the need for rest in 77.9% of studies. Studies also had the same interpretation in 89.5% of studies. Reader confidence was high (86.0% (Early) and 90.3% (Standard p = 0.52. Image quality was good or excellent in 87.4% Early vs 96.8% Standard (p = 0.09). Time between patient check-in and end of stress imaging was 104 ± (Standard) to 60 ± 18 minutes (Early) (p < 0.001).

CONCLUSION

Early post-injection stress-only imaging using CZT SPECT/CT appears promising with Tc-99m tetrofosmin with similar image quality, reader confidence, diagnosis, and need for a rest scan.

Coronary vascular dysfunction is associated with increased risk of death in patients with peripheral artery disease

BACKGROUND

Peripheral artery disease (PAD) and coronary vascular dysfunction are common in patients with cardiometabolic disease. Neither the prevalence of coronary vascular dysfunction among patients with PAD nor the prognostic impact with these two conditions present together has been well studied.

METHODS

Consecutive patients who underwent PET MPI were analyzed for presence of coronary vascular dysfunction [myocardial blood flow reserve (MBFR) < 2]. Cox regression was used to examine the association of reduced MBFR with mortality in patients with PAD, as well as the association of comorbid MBFR < 2 and PAD with all-cause death.

RESULTS

Among 13,940 patients, 1936 (14%) had PAD, 7782 (56%) had MBFR < 2 and 1346 (10%) had both PAD and MBFR < 2. Reduced MBFR was very common (69.5%) and was associated with increased risk of all-cause death (HR 1.69, 95%CI 1.32, 2.16, p < 0.01) in patients with PAD. Patients with both PAD and MBFR < 2, and those with either PAD or reduced MBFR had increased risk of death compared to those with neither condition: PAD + MBFR < 2 [(HR 95%CI), 2.30; 1.97-2.68], PAD + MBFR ≥ 2 (1.37; (1.08-1.72), PAD - MBFR < 2 (1.98; 1.75-2.25), p < 0.001 for all).

CONCLUSION

Coronary vascular dysfunction was common in patients with PAD and was associated with increased risk of death.

Impact of Positron Emission Tomographic Myocardial Perfusion Imaging on Patient Selection for Revascularization

BACKGROUND

Positron emission tomography (PET) myocardial perfusion imaging (MPI) quantifies left ventricular ejection fraction (LVEF) at peak stress. PET LVEF reserve (LVEF-R = stress LVEF - rest LVEF) offers diagnostic and prognostic value.

OBJECTIVES

The purpose of this study was to determine if PET LVEF-R identifies patients with survival benefit postrevascularization.

METHODS

We followed 14,649 unique consecutive patients undergoing 82Rb rest/stress PET MPI from January 2010 to January 2016 (excluding known cardiomyopathy). Adjusted Cox models were built to predict all-cause death, and the 3-way interaction of known coronary artery disease (CAD) (prior myocardial infarction/revascularization), LVEF-R, and 90-day revascularization was tested.

RESULTS

Known CAD was present in 4,982 (34.0%). Ischemia was detected in 5,396 (36.8%; ≥10% in 1,909 [13%]). Mean LVEF-R was 4.2% ± 5.7%, and was ≤0, 1 to 5, and >5 in 3,349 (22.9%), 5,266 (35.9%), and 6,034 (41.2%). Over median follow-up of 3.4 years (IQR: 1.9-5.2 years), 1,324 (8.1%) had 90-day revascularization, and there were 2,192 (15.0%) deaths. In multivariable modeling, there was a significant 3-way interaction among known CAD, LVEF-R, and 90-day revascularization (P = 0.025), such that LVEF-R ≤0 identified patients with survival benefit with 90-day revascularization in those without prior CAD (interaction P = 0.005), independently beyond percent ischemia and myocardial flow reserve. Among patients with known CAD, LVEF-R was not prognostic of death (HR: 0.99; 95% CI: 0.98-1.02; P = 0.98).

CONCLUSIONS

A lack of augmentation or drop in LVEF with vasodilator stress on PET MPI independently identifies patients who have better survival with revascularization within 90 days post-MPI compared with medical therapy, in absence of prior myocardial infarction or revascularization. Multiparametric assessment of ischemia with PET can optimize post-test management.

The Medicare Appropriate Use Criteria Program: A Review of Recommendations for Testing in Coronary Artery Disease

BACKGROUND

Congress established the Appropriate Use Criteria (AUC) Program to reduce unnecessary advanced imaging studies. Organizations that wish to develop AUC can apply to the Centers for Medicare & Medicaid Services (CMS) to qualify as provider-led entities (PLEs) under this program. Variable methods, content, and formatting of PLE-generated AUC could lead to clinician uncertainty about whether an advanced imaging test is appropriate or not.

PURPOSE

To review AUC published by CMS-qualified PLEs focused on advanced imaging tests for coronary artery disease (CAD), a "priority clinical area" identified by CMS.

DATA SOURCES

Publicly available data from the worldwide web searched on 29 August 2022.

STUDY SELECTION

Approved AUC with recommendations related to testing for CAD.

DATA EXTRACTION

Manual review of published AUC by all authors.

DATA SYNTHESIS

Among the 17 CMS-qualified PLEs, only 7 had published AUC related to CAD. Substantial variation in the methods and formatting of these AUCs was observed. The number of clinical scenarios covered ranged from 6 to 210, and the number of advanced imaging methods covered ranged from 1 to 25. When specifically applied to clinical scenarios, many AUC offered no guidance on appropriateness; those that did conflicted with respect to appropriateness.

LIMITATION

Other CMS-identified priority clinical areas were not evaluated.

CONCLUSION

CMS-qualified AUC for imaging of CAD are heterogeneous and sometimes discrepant, creating substantial potential for uncertainty among clinicians seeking to provide their patients with appropriate imaging tests.

PRIMARY FUNDING SOURCE

No funding was received for this study.

Hyperfractionated Cyclophosphamide and Dexamethasone Alone or in Combination with Daratumumab and/or Carfilzomib for the Treatment of Relapsed or Refractory Multiple Myeloma: A Single-Center Retrospective Analysis

BACKGROUND

Hyperfractionated cyclophosphamide and dexamethasone (HyperCd) alone, or with carfilzomib(K) and/or daratumumab(D), represents a potential treatment option when rapid disease control is needed for patients with aggressive presentations of relapsed/refractory multiple myeloma (RRMM).

PATIENTS AND METHODS

This is a single-center, retrospective analysis of adult patients with RRMM who received HyperCd with or without K and/or D between May 1, 2016 and August 1, 2019 at the University of Texas MD Anderson Cancer Center. We here report treatment response and safety outcomes.

RESULTS

Data from 97 patients, 12 with plasma cell leukemia (PCL), were reviewed in this analysis. Patients had had a median of 5 prior lines of therapy and received a median of 1 consecutive cycle of hyperCd-based therapy. The overall response rate (ORR) of all patients was 71.8% (HyperCd 75%, HyperCdK 64.3%, D-HyperCd 73.3%, and D-HyperCdK 76.9%). Median progression-free survival and overall survival among all patients was 4.3 months (HyperCd 3.1 months, HyperCdK 4.5 months, D-HyperCd 3.3 months, and D-HyperCdK 6 months) and 9.0 months (HyperCd 7.4 months, HyperCdK 9.0 months, D-HyperCd 7.5 months, and D-HyperCdK 15.2 months), respectively. Grade 3/4 hematologic toxicities were common, thrombocytopenia being the most frequent at 76%. Notably, 29-41% of patients per treatment group had existing grade 3/4 cytopenias at initiation of hyperCd-based therapy.

CONCLUSION

HyperCd-based regimens provided rapid disease control among MM patients, even when heavily pre-treated and with few remaining treatment options. Grade 3/4 hematologic toxicities were frequent, but manageable with aggressive supportive care.

Improved Performance of PET Myocardial Perfusion Imaging Compared to SPECT in the Evaluation of Suspected CAD

PURPOSE OF REVIEW

Myocardial perfusion imaging (MPI) with single photon emission computed tomography (SPECT) has played a central role in the non-invasive evaluation of patients with obstructive coronary artery disease (CAD) for decades. In this review, we discuss the key differences and advantages of positron emission tomography (PET) MPI over SPECT MPI as it relates to the diagnosis, prognosis, as well as clinical decision-making in patients with suspected CAD.

RECENT FINDINGS

Stress-induced perfusion abnormalities on SPECT help estimate presence, extent, and location of ischemia and flow-limiting obstructive CAD, help with risk stratification, and serve as a gatekeeper to identify patients who will benefit from downstream revascularization versus medical management. Some of the major limitations of SPECT include soft-tissue attenuation artifacts, underestimation of ischemia due to reliance on relative perfusion assessment, and longer protocols with higher radiation dose when performed with traditional equipment. PET MPI addresses most of these limitations and offers better quality images, higher diagnostic accuracy along with shorter protocols and lower radiation dose to the patient. A special advantage of PET scanning lies in the ability to quantify absolute myocardial blood flow and assess true extent of epicardial involvement along with identifying non-obstructive phenotypes of CAD such as diffuse atherosclerosis and microvascular dysfunction. In addition, stress acquisition at/near peak stress with PET allows us to measure left ventricular ejection fraction reserve and myocardial blood flow reserve, which help with identifying patients at a higher risk of future cardiac events and optimally select candidates for revascularization. The several technical advantages of PET MPI position as a superior method to diagnose obstructive and non-obstructive phenotypes of ischemic heart disease affecting the entirety of the coronary circulation offer incremental value for risk stratification and guide post-test management strategy for patients with suspected CAD.

PET for Detection and Reporting Coronary Microvascular Dysfunction: A JACC: Cardiovascular Imaging Expert Panel Statement

Angina pectoris and dyspnea in patients with normal or nonobstructive coronary vessels remains a diagnostic challenge. Invasive coronary angiography may identify up to 60% of patients with nonobstructive coronary artery disease (CAD), of whom nearly two-thirds may, in fact, have coronary microvascular dysfunction (CMD) that may account for their symptoms. Positron emission tomography (PET) determined absolute quantitative myocardial blood flow (MBF) at rest and during hyperemic vasodilation with subsequent derivation of myocardial flow reserve (MFR) affords the noninvasive detection and delineation of CMD. Individualized or intensified medical therapies with nitrates, calcium-channel blockers, statins, angiotensin-converting enzyme inhibitors, angiotensin II type 1-receptor blockers, beta-blockers, ivabradine, or ranolazine may improve symptoms, quality of life, and outcome in these patients. Standardized diagnosis and reporting criteria for ischemic symptoms caused by CMD are critical for optimized and individualized treatment decisions in such patients. In this respect, it was proposed by the cardiovascular council leadership of the Society of Nuclear Medicine and Molecular Imaging to convene thoughtful leaders from around the world to serve as an independent expert panel to develop standardized diagnosis, nomenclature and nosology, and cardiac PET reporting criteria for CMD. This consensus document aims to provide an overview of the pathophysiology and clinical evidence of CMD, its invasive and noninvasive assessment, standardization of PET-determined MBFs and MFR into "classical" (predominantly related to hyperemic MBFs) and "endogen" (predominantly related to resting MBF) normal coronary microvascular function or CMD that may be critical for diagnosis of microvascular angina, subsequent patient care, and outcome of clinical CMD trials.

Reasons for discordance between positron emission tomography (PET) myocardial perfusion imaging (MPI) results and subsequent management

BACKGROUND

Referral patterns to coronary angiography following positron emission tomography (PET) myocardial perfusion imaging (MPI) and reasons for non-referral following abnormal PET MPI are largely unknown.

METHODS

Referral rates to coronary angiography within 90 days post PET MPI were determined. A random subset of 100 patients with severe (≥ 10%) ischemia on MPI between 2014-16 who were not referred for angiography were examined to better understand reasons as to why patients with high-risk MPI findings did not undergo coronary angiography.

RESULTS

Among 19,282 unique patients, overall rate of 90-day coronary angiography was 18.5% (3574/19282). Among patients with severe ischemia, 64.1% (1930/3011) underwent angiography within 90 days; the rate was lower in those with mild-moderate (20.6% [1010/4898]) and no ischemia (5.6% [634/11373]). In the random sample of 100 patients, the most common physician reasons for non-referral were uncertainty regarding whether the test results were responsible for the patient's presenting symptoms, renal failure, and patient age, frailty, or cognitive status, while patient preference for medical management was by far the most common patient reason.

CONCLUSION

Referral rates for coronary angiography after PET correlate with severity of ischemia. However, there appear to be opportunities to reconsider testing for instances when results will not change clinical management.

Prognostic Relationship Between Coronary Artery Calcium Score, Perfusion Defects, and Myocardial Blood Flow Reserve in Patients With Suspected Coronary Artery Disease

BACKGROUND

Coronary artery calcium score (CACS) is an anatomic measure of calcified atherosclerosis. Myocardial perfusion defects and reduced myocardial blood flow reserve (MBFR) are physiological measures of ischemia and coronary circulatory health. We aimed to assess the relative prognostic importance of MBFR, perfusion defects, and CACS in patients with suspected coronary artery disease.

METHODS

A total of 5983 consecutive patients without known history of coronary artery disease or cardiomyopathy, who underwent a CACS and ⁸²Rb positron emission tomography myocardial perfusion imaging between 2010 and 2016, were followed for all-cause death (n=785) over median of 3 years. Prognostic value was assessed using multivariable Cox regression models, and incremental risk discrimination for imaging variables was evaluated by comparing model c-indices after adjusting for clinical risk factors (RF).

RESULTS

Mean age was 67.1 years, 60% were female, and 83% were symptomatic. CACS was 0 in 22%, abnormal perfusion in 19%, and MBFR <2 in 53.3%. When added to RF, the model with MBFR had the best fit (c=0.78, P<0.0001). Addition of CACS to model with RF and perfusion (c=0.77) offered modest improvement in discrimination over the model with RF and perfusion (c=0.76, P=0.02). Adding CACS to a model with RF, perfusion, and MBFR did not provide incremental prognostic value (c=0.785 for both, P=0.16). CACS and MBFR both had independent prognostic value in patients with normal and abnormal myocardial perfusion imaging. Even among patients with CACS of 0, MBFR <2 was present in 37.8%, being associated with higher risk of death (hazard ratio per 0.1↓, 1.10 [1.04-1.15]; P<0.001), but perfusion defects were not.

CONCLUSIONS

Use of anatomic testing such as CACS of 0 to avoid myocardial perfusion imaging in symptomatic patients could lead to missing microvascular dysfunction in 4 out of 10 patients, a finding associated with a high mortality risk. Higher CACS was independently associated with the risk of death but did not provide incremental prognostic value over positron emission tomography with MBFR.

Relationship Between Myocardial Perfusion Imaging Abnormalities on Positron Emission Tomography and Anginal Symptoms, Functional Status, and Quality of Life

BACKGROUND

Myocardial perfusion imaging (MPI) identifies abnormalities that occur early in the ischemic cascade leading to angina. Our aim was to study the association between ischemic measures on positron emission tomography MPI and patients' health status; their symptoms, function, and quality of life.

METHODS

Health status was collected using the Seattle Angina Questionnaire (SAQ-7, 0-100, higher=better) and Rose Dyspnea Score (RDS) on 1515 outpatients with known or suspected coronary artery disease presenting for clinically indicated pharmacological ⁸²Rb positron emission tomography MPI from July 2018 to July 2019. Adjusted multivariable ordinal regression models were used to assess the association between MPI findings of ischemia and the SAQ physical limitation, angina frequency, quality of life, summary score, and the RDS.

RESULTS

The mean SAQ and RDS scores of the cohort (mean age 71.7 years, 55% male, 37.6% prior myocardial infarction or revascularization) were 73.8±28.6 (physical limitation), 87.4±21.7 (angina frequency), 79.0±26.1 (quality of life), 81.3±19.0 (summary score), and 2±2 (RDS). No perfusion, flow or function abnormalities were significantly associated with SAQ angina frequency scores. Low left ventricular ejection fraction reserve (≤0%), low global and regional myocardial blood flow reserve (<2) were independently associated with worse SAQ Physical Limitation score, SAQ summary score, and RDS (30% to 57% greater odds; all P≤0.01), but reversible perfusion defects were not.

CONCLUSIONS

Impaired augmentation of left ventricular ejection fraction and myocardial blood flow with stress is associated with significant angina-associated functional limitation, health status, and dyspnea in patients who underwent positron emission tomography MPI, but not the frequency of their angina. Future studies should evaluate whether therapies that improve stress-induced abnormalities in systolic function and myocardial flow may improve patients' health status.

Stress myocardial perfusion imaging in patients presenting with syncope: Comparison of PET vs. SPECT

BACKGROUND

The role of myocardial perfusion imaging (MPI) in patients with suspected coronary artery disease (CAD) presenting with syncope is controversial. We aimed to determine diagnostic yield of MPI for evaluation of syncope in patients without known CAD, as a function of pre-test patient risk and test modality (PET vs SPECT).

METHODS

Between 1/2010 and 12/2016, 1324 consecutive patients presenting with syncope without known CAD underwent MPI with PET (n = 640) or SPECT (n = 684). Rates of abnormal MPI (summed difference score (SDS) > 2 or left ventricular ejection fraction (LVEF) reserve ≤ 0 for PET and SDS > 2 or post-stress LVEF ≤ 45% for SPECT) were determined among patients stratified by pre-test risk. In patients who were referred for coronary angiography, diagnostic yield of obstructive CAD was calculated in the overall cohort as well as in a propensity-matched cohort compared to patients without syncope.

RESULTS

Abnormal MPI was noted in 36.5% (201/551) of patients who had PET compared with 13.0% (87/671) who had SPECT (P < 0.001), which is largely related to higher comorbidity burden and greater pre-test CAD risk in the PET population. Among patients who had an abnormal MPI, 8.5% (47/551) with PET and 0.7% (5/671) with SPECT were found to have obstructive CAD if referred for coronary angiography. Patients at intermediate-high pre-test risk had a higher proportion of abnormal MPIs and obstructive CAD as compared to those at low risk in both the PET and SPECT cohorts. The rate of abnormal testing and diagnostic yield of PET MPI was similar and proportionate to pre-test likelihood among matched patients with and without syncope.

CONCLUSIONS

Among patients referred for PET MPI with syncope at an intermediate-high pre-test CAD risk, 1 in 3 had an abnormal MPI and 1 in 10 had obstructive CAD. The value of MPI was related to pre-test risk as opposed to the presence of syncope, and MPI testing with PET or SPECT in the low-risk population was low value.

Relative Prognostic Significance of Positron Emission Tomography Myocardial Perfusion Imaging Markers in Cardiomyopathy

BACKGROUND

Rubidium-82 positron emission tomography myocardial perfusion imaging provides measurements of perfusion, myocardial blood flow and reserve (MBFR), and changes in left ventricular ejection fraction (LVEF) at rest and peak stress. Although all of these variables are known to provide prognostic information, they have not been well studied in patients with heart failure due to reduced LVEF.

METHODS

Between 2010 and 2016, 1255 consecutive unique patients with LVEF≤40% were included in this study who underwent rubidium-82 positron emission tomography myocardial perfusion imaging and did not have subsequent revascularization within 90 days. Perfusion assessment was scored semiquantitatively, and LVEF reserve (stress-rest LVEF) and global MBFR (stress/rest MBF) were quantified using automated software. Cox proportional hazards models adjusted for 14 clinical and 7 test characteristics were used to define the independent prognostic significance of MBFR on all-cause mortality.

RESULTS

Of 1255 patients followed for a mean of 3.2 years, 454 (36.2%) died. After adjusting for clinical variables, the magnitude of fixed and reversible perfusion defects was prognostic of death (P=0.02 and 0.01, respectively), while the rest LVEF was not (P=0.18). The addition of LVEF reserve did not add any incremental value, while the addition of MBFR revealed incremental prognostic value (hazard ratio per 0.1 unit decrease in MBFR=1.08 [95% CI, 1.05-1.11], P<0.001) with fixed and reversible defects becoming nonsignificant (P=0.07 and 0.29, respectively). There was no interaction between MBFR and cause of cardiomyopathy (ischemic versus nonischemic).

CONCLUSIONS

In patients with a known cardiomyopathy who did not require early revascularization, reduced MBFR as obtained by positron emission tomography myocardial perfusion imaging is associated with all-cause mortality while other positron emission tomography myocardial perfusion imaging measures were not.

Psychometric Evaluation of the Kansas City Cardiomyopathy Questionnaire in Men and Women With Heart Failure

BACKGROUND

The Kansas City Cardiomyopathy Questionnaire (KCCQ) has been psychometrically evaluated in multiple heart failure (HF) populations, but the comparability of its psychometric properties between men and women is unknown.

METHODS

Data from 3 clinical trials (1 in stable HF with preserved ejection fraction, 1 each in stable and acute HF with reduced ejection fraction) and 1 prospective cohort study (stable HF with reduced ejection fraction), incorporating 6773 men and 3612 women with HF, were used to compare the construct validity, internal and test-retest reliability, ability to detect change, predict mortality and hospitalizations and minimally important differences between the 2 sexes. Interactions of the KCCQ overall summary and subdomain scores by sex were independently examined.

RESULTS

The KCCQ-Overall Summary score correlated well with New York Heart Association functional class in both sexes across patients with stable (correlation coefficient: -0.40 in men versus -0.49 in women) and acute (-0.37 in men versus -0.34 in women) HF. All KCCQ subdomains demonstrated concordant relationships with relevant comparison standards with no significant interactions by sex in 19 of 21 of these construct validity analyses. All KCCQ scores were equally predictive and other psychometric evaluations showed similar results by sex: test-retest reliability (intraclass correlation coefficient 0.94 in men versus 0.92 in women), responsive to change (standardized response mean 1.01 in both sexes), as were the minimally important differences and internal reliability.

CONCLUSIONS

The psychometric properties of the KCCQ, in terms of validity, prognosis, reliability, and sensitivity to change, are comparable in men and women with HF with preserved ejection fraction and HF with reduced ejection fraction.

Development and Piloting of a Patient-Centered Report Design for Stress Myocardial Perfusion Imaging Results

IMPORTANCE

The management of coronary disease epitomizes the call to better engage patients in shared medical decision-making. Myocardial perfusion imaging (MPI) is the foundation of diagnosis, risk stratification, and subsequent therapy; however, MPI reports are currently interpretable by specialists but not patients.

OBJECTIVE

To design and test a patient-centered report for stress MPI test results.

DESIGN, SETTING, AND PARTICIPANTS

This qualitative study of outpatients who underwent an MPI stress test and clinicians used a mixed methods approach. Phase 1 (December 2018 to July 2019) used qualitative methods to design a patient-centered reporting tool, with 5 focus groups with 36 patients and 2 focus groups with 27 clinicians. Phase 2 (June to September 2019) consisted of pilot testing the reporting tool with feedback from a structured survey given to patients who received MPI reports before and after implementing the tool.

MAIN OUTCOMES AND MEASURES

Key themes around patient experiences with the current MPI reporting and their desire for a more useful report were identified, which led to a sample reporting tool after serial iterations with feedback. Differences in patient knowledge and engagement were assessed between patients before and after implementation of the new reporting tool using χ2 tests.

RESULTS

From patient focus groups (26 patients; mean [SD] age, 66.3 [9.6] years, 9 [35%] women), 3 themes on the inadequacies of current MPI reporting were identified: (1) inconsistent delivery of results, (2) use of medical jargon, and (3) unclear posttest course. We identified 5 themes for a more patient-centered MPI report: desire for written information, discussion of the report with medical personnel, presentation of results in simple language with use of visual graphics, comparisons with normal results, and personalized risk estimates. In a pilot survey with 123 patients split into a pre-implementation group (69 patients; mean [SD] age, 68.2 [8.5] years; 27 [51%] women) and a postimplementation group (54 patients; mean [SD] age, 66.4 [8.7] years; 30 [56%] women), the patient-centered report led to more patients reading the entire report (45 [83%] vs 46 [67%]; P = .04) and improved knowledge of future risk of cardiac events (41 [76%] vs 20 [29%]; P < .001). There was also a numerically higher percentage of patients who found the report easy to read (45 [83%] vs 44 [68%]; P = .05) and understand (42 [78%] vs 43 [66%]; P = .16), although these results were not statistically significant.

CONCLUSIONS AND RELEVANCE

This study identified key elements of a patient-centered report design for stress MPI test results, which improved patient engagement and knowledge. These preliminary data support further implementation and study of a more patient-centered MPI report.

Relationship between coronary artery calcium score and myocardial blood flow reserve in patients with suspected coronary artery disease

Funding Acknowledgements

Type of funding sources: None.

Background

Both the Coronary Artery Calcium Score (CACS), a non-invasive surrogate for atherosclerotic burden, and reduced myocardial blood flow reserve (MBFR) with normal perfusion, a non-invasive surrogate for coronary vasomotor dysfunction, independently predict future cardiovascular events. The relationship between CACS and MBFR, and potential clinical factors affecting it, is not well understood.

Methods

Among 9467 consecutive patients without known history of CAD who had normal perfusion on 82Rb PET-CT and a concomitantly measured CACS between 01/2010 - 06/2020 within our health system, we assessed the relationship between CACS and MBFR. Multiple linear regression was used to predict MBFR using CACS, adjusted for age, sex, BMI, risk factors, symptoms, resting LVEF and vital signs. Interactions of age, sex, diabetes, and symptoms with CACS were assessed to evaluate if they modified the relationship of CACS with MBFR.

Results

Mean age (SD) of the study cohort was 66.4 (12.6) years, 64% were women, 64% had chest pain and 47% had dyspnea. Reduced MBFR (&lt;2) was present in 44% and CAC &gt;0 in 74% of patients.  There was a modest inverse correlation between MBFR and CACS, r= - 0.18, p = &lt; 0.0001 (Figure). In adjusted analyses, CACS (β for CAC per 100 = -0.013 [95% CI: -0.015, -0.010]) was weakly associated with MBFR, and age, sex, diabetes, or symptoms did not modify this relationship (all interaction p-values &gt;0.1). Older age, female sex, presence of hypertension, diabetes, dyspnea, lower LVEF, higher baseline HR and higher CACS independently predicted reduced MBFR, but explained only 20% of the variance in MBFR (R2 =0.20).

Conclusion

There is a weak relationship between CACS and MBFR, which is not modified by age, sex, symptoms, or other CV risk factors. Coronary calcium burden does not completely reflect the overall disease activity within the coronary circulation, and measures of coronary vasomotor function such as MBFR may offer complementary information on CAD risk to that provided by the total burden of calcified atherosclerosis.

Myocardial blood flow reserve assessed by positron emission tomography myocardial perfusion imaging identifies patients with a survival benefit from early revascularization

AIMS

Positron emission tomography (PET) myocardial perfusion imaging (MPI) can non-invasively measure myocardial blood flow reserve (MBFR). We aimed to examine whether MBFR identifies patients with a survival benefit after revascularization, helping to guide post-test management.

METHODS AND RESULTS

We examined all-cause mortality in 12 594 consecutive patients undergoing Rb82 rest/stress PET MPI from January 2010 to December 2016, after excluding those with cardiomyopathy, prior coronary artery bypass surgery (CABG), and missing MBFR. Myocardial blood flow reserve was calculated as the ratio of stress to rest absolute myocardial blood flow. A Cox model adjusted for patient and test characteristics, early revascularization (percutaneous coronary intervention or CABG ≤90 days of MPI), and the interaction between MBFR and early revascularization was developed to identify predictors of all-cause mortality. After a median follow-up of 3.2 years, 897 patients (7.1%) underwent early revascularization and 1699 patients (13.5%) died. Ischaemia was present in 4051 (32.3%) patients, with 1413 (11.2%) having ≥10% ischaemia. Mean MBFR was 2.0 ± 1.3, with MBFR <1.8 in 4836 (38.5%). After multivariable adjustment, every 0.1 unit decrease in MBFR was associated with 9% greater hazard of all-cause death (hazard ratio 1.09, 95% confidence interval 1.08-1.10; P < 0.001). There was a significant interaction between MBFR and early revascularization (P < 0.001); such that patients with MBFR ≤1.8 had a survival benefit with early revascularization, regardless of type of revascularization or level of ischaemia.

CONCLUSION

Myocardial blood flow reserve on PET MPI is associated with all-cause mortality and can identify patients who receive a survival benefit with early revascularization compared to medical therapy. This may be used to guide revascularization, and prospective validation is needed.

Variability in utilization of diagnostic imaging tests in patients with symptomatic peripheral artery disease

AIM

Imaging can help guide management in peripheral arterial disease (PAD) with symptoms refractory to medical treatment. However, there are no set guidelines to determine when physicians should seek further imaging in patients with PAD for the assessment of new, persistent or worsening symptoms. This study describes the rates and variability in non-invasive and invasive imaging for patients presenting to vascular specialty clinics for symptomatic PAD.

METHODS

Patients (n=1,275) with a new PAD diagnosis or exacerbation of PAD symptoms were enrolled from 16 vascular clinics. Hierarchical logistic regression models were used to estimate the referral rates for 1) non-invasive and 2) invasive imaging tests, after adjusting for patient demographics, disease characteristics, PAQ summary score, PAD performance measures and country. Median Odds Ratios (MOR) were calculated to examine the variability across sites and providers.

RESULTS

Mean ABI was 0.67 ± 0.19. There were 690 (54.1%) patients who had imaging, of which 62 (9.0%) had invasive imaging. Imaging rates ranged from 8.6% to 98.6% across sites. The MOR for use of imaging for site was 3.36 (p < 0.001) and provider 3.49 (p < 0.001). The variability was explained primarily by (R² = 29%) country followed by patient-level factors, provider and lastly site (R² = 17%, 14%, and 13%, respectively).

CONCLUSION

There is wide variation in the use of imaging for patients presenting with new onset or recent exacerbations of their PAD. Country, followed by provider and site, were most strongly associated with this variability after adjusting for patient characteristics.

Global patterns of comprehensive cardiovascular risk factor control in patients with type 2 diabetes mellitus: Insights from the DISCOVER study

AIM

To investigate global patterns of cardiovascular risk factor control in patients with type 2 diabetes mellitus (T2D).

METHODS

DISCOVER is an international, observational cohort study of patients with T2D beginning second-line glucose-lowering therapy. Risk factor management was examined among eligible patients (ie, those with the risk factor) at study baseline. Inter-country variability was estimated using median odds ratios (MORs).

RESULTS

Among 14 343 patients with T2D from 34 countries, the mean age was 57.4 ± 12.0 years and the median (interquartile range) duration of T2D was 4.2 (2.0-8.0) years; 11.8% had documented atherosclerotic cardiovascular disease (ASCVD). Among eligible patients, blood pressure was controlled in 67.5% (9284/13756), statins were prescribed in 43.7% (5775/13208), angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers were prescribed in 55.6% (5292/9512), aspirin was prescribed in 53.3% of those with established ASCVD (876/1645), and 84.4% (12 102/14343) were non-smoking. Only 21.5% of patients (3088/14343) had optimal risk factor management (defined as control of all eligible measures), with wide inter-country variability (10%-44%), even after adjusting for patient and site differences (MOR 1.47, 95% confidence interval 1.24-1.66).

CONCLUSION

Globally, comprehensive control of ASCVD risk factors is not being achieved in most patients, with wide variability among countries unaccounted for by patient and site differences. Better country-specific strategies are needed to implement comprehensive cardiovascular risk factor control consistently in patients with T2D to improve long-term outcomes.

Association of Diabetes Mellitus With Health Status Outcomes in Patients With Peripheral Artery Disease: Insights From the PORTRAIT Registry

Background

Patients with peripheral artery disease (PAD) and coexisting diabetes mellitus (DM) have greater PAD progression and adverse limb events. Our aim was to study whether PAD‐specific health status differs by DM.

Methods and Results

The PORTRAIT (Patient‐Centered Outcomes Related to Treatment Practices in Peripheral Arterial Disease: Investigating Trajectories) trial is a 16‐center international registry that includes patients with recent exacerbations or new‐onset symptomatic PAD presenting to specialty clinics. We assessed PAD‐specific health status initially and at 3, 6, and 12 months (Peripheral Artery Questionnaire [PAQ]). We used hierarchical, multivariable, linear regression, and repeated measures analyses to study the association between DM and baseline health status initially and over 3 to 12 months. Models were adjusted for demographics, socioeconomic factors, PAD severity, comorbidities, and psychosocial characteristics. The interaction of DM with PAD revascularization on 3‐ to 12‐month health status was also tested. Of 1204 patients, 398 (33%) had DM (94% type 2). Patients with versus those without DM had lower unadjusted PAQ summary scores at baseline and 3, 6, and 12 months (46.1 versus 50.8, 63.6 versus 68.2, 65.7 versus 71.7, and 65.4 versus 72.6; P≤0.01). In fully adjusted models, the effect of DM on baseline (mean difference, −0.65; 95% CI, −2.86 to 1.56 [P=0.56]) and over 3‐ to 12‐month PAQ summary scores (mean difference, −1.59; 95% CI, −4.06 to 0.88 [P=0.21]) was no longer significant. Twelve‐month health status gains following revascularization were similar in both groups (P=0.69).

Conclusions

Patients with PAD with coexisting DM have poorer health status, mostly explained by the differences in their psychosocial and other comorbidity burden. Patients with PAD and DM versus those without DM experience similar health status benefits following PAD revascularization.

Drivers of radiation dose reduction with myocardial perfusion imaging: A large health system experience

BACKGROUND

Despite increasing emphasis on reducing radiation exposure from myocardial perfusion imaging (MPI), the use of radiation-sparing practices (RSP) at nuclear laboratories remains limited. Defining real-world impact of RSPs on effective radiation dose (E) can potentially further motivate their adoption.

METHODS

MPI studies performed between 1/2010 and 12/2016 within a single health system were included. Mean E was compared between sites with 'basic' RSP (defined as elimination of thallium-based protocols and use of stress-only (SO) imaging on conventional single photon emission computed tomography (SPECT) cameras) and those with 'advanced' capabilities (sites that additionally used solid-state detector (SSD) SPECT cameras, advanced post-processing software (APPS) or positron emission tomography (PET) imaging), after matching patients by age, gender, and weight. Contributions of individual RSP to E reduction were determined using multiple linear regression after adjusting for factors affecting tracer dose.

RESULTS

Among 55,930 MPI studies performed, the use of advanced RSP was associated with significantly lower mean E compared to basic RSP (7 ± 5.6 mSv and 16 ± 5.4 mSv, respectively; P < 0.001), with a greater likelihood of achieving E < 9 mSv (65.7% vs. 10.8%, respectively; OR 15.8 [95% CI 14 to 17.8]; P < 0.0001). Main driver of E reduction was SO-SSD SPECT (mean reduction = 11.5 mSv), followed by use of SO-SPECT + APPS (mean reduction = 10.1 mSv), ;ET (mean reduction = 9.7 mSv); and elimination of thallium protocols (mean reduction = 9.1 mSv); P < 0.0001 for all comparisons.

CONCLUSION

In a natural experiment with implementation of radiation-saving practices at a large health system, stress-only protocols used in conjunction with modern SPECT technologies, the use of PET and elimination of thallium-based protocols were associated with greatest reductions in radiation dose. Availability of several approaches to dose reduction within a health system can facilitate achievement of targeted radiation benchmarks in a greater number of performed studies.

Temporal trends in test utilization and prevalence of ischaemia with positron emission tomography myocardial perfusion imaging

AIMS

To examine whether test utilization and prevalence of ischemia with positron emission tomography (PET) myocardial perfusion imaging (MPI) follow the previously described trends with single photon computed tomography (SPECT).

METHODS AND RESULTS

MPI studies performed between January 2003 and December 2017 were identified. Number of PET and SPECT MPI studies performed per year was determined. Trends in the proportion of studies showing any ischaemia (>0%) with both modalities were compared before and after adjusting for baseline differences in patient characteristics using propensity scores. Interaction between imaging modality and year of testing was examined using modified Poisson regression. A total of 156 244 MPI studies were performed (30% PET and 70% SPECT). Between 2003 and 2017, the number of PET studies increased from 18 to 61 studies/1000 patient encounters, while SPECT volumes declined from 169 to 34/1000 patient encounters (P < 0.001 for within-group comparisons). The prevalence of any ischaemia in SPECT-tested patients declined from 53.9% to 28.3% between 2003 and 2017, whereas ischaemia prevalence in PET-tested patients declined from 57.2% to 38.2% (P < 0.001 for within-modality comparisons), with more PET studies showing ischaemia compared to SPECT [relative risk (RR) 1.44, 95% confidence interval (CI) 1.42-1.47; P < 0.001]. After propensity score matching of 26 066 patients tested with SPECT with 26 066 patients tested with PET, the between-modality difference in ischaemia prevalence was significantly attenuated, with a slightly higher overall likelihood of detecting ischaemia with PET compared to SPECT (RR 1.08, 95% CI 1.05-1.11; P < 0.001).

CONCLUSIONS

Utilization of PET MPI at a large-volume referral centre increased significantly between 2003 and 2017. Despite a significant decrease in the prevalence of ischaemia with SPECT and PET during the same period, the decline was less with PET, perhaps related to baseline risk of tested patients.

Mental health concerns in patients with symptomatic peripheral artery disease: Insights from the PORTRAIT registry

OBJECTIVES

To document the prevalence and patient profiles of mental health concerns in patients with peripheral artery disease (PAD) seen in the vascular specialty setting.

METHODS

In a cohort of 1275 patients presenting to 16 specialty clinics with new or worsening claudication, symptoms of depression, anxiety, and stress were quantified in 957 patients. The Patient Health Questionnaire-8 (PHQ-8), Generalized Anxiety Disorder scale-2 (GAD-2), and Perceived Stress Scale-4 (PSS-4) were assessed for mental health concerns at the initial PAD work-up and repeated 12 months later. PHQ-8 ≥ 10, GAD-2 ≥ 3 and PSS-4 ≥ 6 were considered significant for depression, anxiety and stress respectively. Patient characteristics were compared in groups divided by presence of 0, 1, 2 or all 3 mental health concerns.

RESULTS

On the initial office visit, 336/957 (35%) of patients had high levels of at least one of the three mental health concerns. At both baseline and 12 months, high levels of perceived stress were most often reported (28.7% and 17.5% respectively), followed by symptoms of depression (14.1% and 8.9%) and then anxiety (8.3% and 5.7%). Patients with mental health concerns were more often female, younger, had more financial strain, less social support, and worse perceived health status.

CONCLUSIONS

Mental health concerns, particularly stress, are highly prevalent in patients with PAD, especially upon first presenting with new or worsening symptoms. The role of stress and how it may impede successful PAD management and impact subsequent outcomes warrants further investigation.

Changes in Health and Well-Being during Residents' Training

OBJECTIVES

Previous studies have characterized the negative effects of graduate medical education on physicians; however, there is limited longitudinal data on how physicians' well-being changes during their training. This study aimed to demonstrate and quantify changes to trainees' wellness and health habits during the course of their first 2 years of graduate medical education.

METHODS

A longitudinal survey study of postgraduate year 1 trainees at the Cleveland Clinic was administered at 3 time points: the initial survey during orientation week, a second survey at 1 year, and a final survey at 2 years.

RESULTS

Of the 170 trainees contacted, 59 (35%) completed the initial survey and 34 (58%) completed the first follow-up survey. Between the initial survey and the first follow-up survey, respondents reported that their health was worse than the prior year (P < 0.001). They also reported sleeping on average 1 hour less per night and exercising on average one fewer day per week. The number of individuals who reported not eating breakfast increased by 22%, whereas the number of individuals eating out at lunch more than doubled. Twenty-seven people completed the second follow-up survey. Between the first follow-up survey and the final survey, respondents gained on average 2.12 lb (P = 0.039). Breakfast, lunch, and sleeping habits persisted through the second follow-up survey.

CONCLUSIONS

Residents' health and wellness habits deteriorated during internship and did not improve in the second year of residency. Efforts to promote healthy habits in this population should be a priority.

Underutilization of Evidence-Based Smoking Cessation Support Strategies Despite High Smoking Addiction Burden in Peripheral Artery Disease Specialty Care: Insights from the International PORTRAIT Registry

Background

Smoking is the most important risk factor for peripheral artery disease (PAD). Smoking cessation is key in PAD management. We aimed to examine smoking rates and smoking cessation interventions offered to patients with PAD consulting a vascular specialty clinic; and assess changes in smoking behavior over the year following initial visit.

Methods and Results

A total of 1272 patients with PAD and new or worsening claudication were enrolled at 16 vascular specialty clinics (2011–2015, PORTRAIT (Patient‐Centered Outcomes Related to Treatment Practices in Peripheral Arterial Disease: Investigating Trajectories) registry). Interviews collected smoking status and cessation interventions at baseline, 3, 6, and 12 months. Among smokers, transition state models analyzed smoking transitions at each time point and identified factors associated with quitting and relapse. On presentation, 474 (37.3%) patients were active, 660 (51.9%) former, and 138 (10.8%) never smokers. Among active smokers, only 16% were referred to cessation counseling and 11% were prescribed pharmacologic treatment. At 3 months, the probability of quitting smoking was 21%; among those continuing to smoke at 3 months, the probability of quitting during the next 9 months varied between 11% and 12% (P<0.001). The probability of relapse among initial quitters was 36%. At 12 months, 72% of all smokers continued to smoke.

Conclusions

More than one third of patients with claudication consulting a PAD provider are active smokers and few received evidence‐based cessation interventions. Patients appear to be most likely to quit early in their treatment course, but many quickly relapse and 72% of all patients smoking at baseline are still smoking at 12 months. Better strategies are needed to provide continuous cessation support.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01419080.

Extent of Myocardial Ischemia on Positron Emission Tomography and Survival Benefit With Early Revascularization

BACKGROUND

Prior studies with single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) have shown a survival benefit with early revascularization in patients with >10% to 12.5% ischemic myocardium. The relationship among positron emission tomography (PET)-derived extent of ischemia, early revascularization, and survival is unknown.

OBJECTIVES

The purpose of this study was to evaluate the association among percent ischemia on PET MPI, revascularization, and survival.

METHODS

A total of 16,029 unique consecutive patients who were undergoing Rubidium-82 rest-stress PET MPI from 2010 to 2016 were included. Patients with known cardiomyopathy and nondiagnostic perfusion results were excluded. Percent ischemic myocardium was estimated from a 17-segment model. Propensity scoring was used to account for nonrandomized referral to early revascularization (90 days of PET). A Cox model was developed, adjusting for propensity scores for early revascularization and percent ischemia, and an interaction between ischemia and early revascularization was tested.

RESULTS

Median follow-up was 3.7 years. Overall, 1,277 (8%) patients underwent early revascularization and 2,493 (15.6%) died (738 cardiac). Nearly 37% of patients (n = 5,902) had ischemia, with 13.5% (n = 2,160) having ≥10%. In propensity-adjusted analyses, there was a significant interaction between ischemia and early revascularization (p < 0.001 for all-cause and cardiac death), such that patients with greater ischemia had improved survival with early revascularization, with a potential ischemia threshold at 5% (upper limit 95% confidence interval at 10%). There was no differential association between ischemia and early revascularization on death based on history of known coronary artery disease (interaction p = 0.72).

CONCLUSIONS

In a contemporary cohort of patients undergoing PET MPI, patients with greater ischemia had a survival benefit from early revascularization. On exploratory analyses, this threshold was lower than that previously reported for SPECT. These findings require future validation in prospective cohorts or trials.

Randomized Comparison of Clinical Effectiveness of Pharmacologic SPECT and PET MPI in Symptomatic CAD Patients

OBJECTIVES

This study compared the clinical effectiveness of pharmacologic stress myocardial perfusion imaging (MPI) plus positron emission tomography (PET) with single-photon emission computed tomography (SPECT) in patients with known coronary artery disease (CAD) presenting with symptoms suggestive of ischemia.

BACKGROUND

Although PET MPI has been shown to have higher diagnostic accuracy in detecting hemodynamically significant CAD than SPECT MPI, whether this impacts downstream management has not been formally evaluated in randomized trials.

METHODS

This study consisted of a single-center trial in which patients with known CAD and suspected ischemia were randomized to undergo PET or attenuation-corrected SPECT MPI between June 2009 and September 2013. Post-test management was at the discretion of the referring physician, and patients were followed for 12 months. The primary endpoint was diagnostic failure, defined as unnecessary angiography (absence of ≥50% stenosis in ≥1 vessel) or additional noninvasive testing within 60 days of the MPI. Secondary endpoints were post-test escalation of antianginal therapy, referral for angiography, coronary revascularization, and health status at 3, 6, and 12 months.

RESULTS

A total of 322 patients with an evaluable MPI were randomized (n = 161 in each group). At baseline, 88.8% of patients were receiving aspirin therapy, 76.7% were taking beta-blockers, and 77.3% were taking statin therapy. Diagnostic failure within 60 days occurred in only 7 patients (2.2%) (3 [1.9%] in the PET group and 4 [2.5%] in the SPECT group; p = 0.70). There were no significant differences between the 2 groups in subsequent rates of coronary angiography, coronary revascularization, or health status at 3, 6, and 12 months of follow-up (all p values ≥0.20); however, when subjects were stratified by findings on MPI in a post hoc analysis, those with high-risk MPI on PET testing had higher rates of angiography and revascularization on follow-up than those who had SPECT MPI, whereas those undergoing low-risk PET studies had lower rates of both procedures than those undergoing SPECT (interaction between randomized modality ∗high-risk MPI for 12-month catheterization [p = 0.001] and 12-month revascularization [p = 0.09]).

CONCLUSIONS

In this contemporary cohort of symptomatic CAD patients who were optimally medically managed, there were no discernible differences in rates of diagnostic failure at 60 days, subsequent coronary angiography, revascularization, or patient health status at 1 year between patients evaluated by pharmacologic PET compared with those evaluated by SPECT MPI. Downstream invasive testing rates with PET MPI were more consistent with high-risk features than those with SPECT MPI. (Effectiveness Study of Single Photon Emission Computed Tomography [SPECT] Versus Positron Emission Tomography [PET] Myocardial Perfusion Imaging; NCT00976053).

Abstract 166: Blood Pressure Variability and Cardiovascular Outcomes in Heart Failure with Preserved Ejection Fraction

Background: High blood pressure variability (BPV), independent of mean blood pressure, is associated with increased cardiovascular events in patients with hypertension or chronic kidney disease. Heart failure with preserved ejection fraction (HFpEF) is often managed with aggressive blood pressure control, but the association of BPV with cardiovascular outcomes among patients with HFpEF has not been examined.

Methods: We performed a post hoc analysis of the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial. BPV was assessed for each patient as the standard deviation of all available systolic blood pressure measurements (SD-SBP) during follow up. A cox regression analysis, adjusting for demographic, clinical, and blood pressure medication and measurement characteristics (Figure), was performed to assess the independent association of BPV with all-cause death and a composite of cardiovascular death and heart failure hospitalization. BPV was modeled with a spline function with the median SD-SBP (9.95) chosen as reference, and as quartiles with the highest quartile (Q4) as reference

Results: Among 3445 participants at baseline, mean age was 68.6, BMI was 32.1 and 51.5% were female. Over a median follow up of 3.4 years, average SD-SBP was 10.9 mmHg. BPV was associated with the risk of all-cause death [Hazard Ratio (95% CI) vs. Q4: Q1=0.85 (0.65, 1.2) p=0.2, Q2 = 0.75 (0.58, 0.96) p =0.03, Q3 = 0.74 (0.58, 0.93) p=0.01] and composite outcome of cardiovascular death or heart failure hospitalization [Q1 = 0.49 (0.39, 0.63) p < 0.01, Q2 = 0.63 (0.51, 0.77) p<0.01, Q3=0.69 (0.57, 0.83) p<0.01]. The risk of death and the composite outcome appeared to significantly increase as the SD-SBP increased above ~11 mmHg (Figure).

Conclusion: In patients with HFpEF, the risk of all cause death and a composite of cardiovascular death and heart failure hospitalization significantly increased, as the SD-SBP increased beyond 11 mmHg. This association was independent of mean SBP. Whether reducing BPV is a potential therapeutic target in HFpEF requires further study.

Characteristics and Outcomes of Patients With Aortic Stenosis and Chronic Kidney Disease

Background We sought to study longer term survival in patients with aortic stenosis ( AS ) and nondialysis chronic kidney disease ( CKD ). Methods and Results We studied 839 patients (aged 78±9 years and 51% male) with CKD and AS on echocardiogram from 2005 to 2012. Longer term all-cause and cardiovascular mortality was compared with a CKD group without AS , propensity matched for age, sex, race, left ventricular ejection fraction and CKD stage. Cox models were used to evaluate all-cause mortality and competing-risks regression models censored at time of aortic valve replacement to evaluate cardiac mortality in patients with AS and CKD . Overall, 511 (61%), 252 (30%), and 76 (9%) patients had CKD stages 3a, 3b, and 4, respectively; 93% had hypertension, 28% had diabetes mellitus, and 37% had coronary artery disease. In total, 185 (22%) had mild AS, 355 (42%) had moderate AS, and 299 (36%) had severe AS (66 symptomatic). Patients with CKD and AS had higher cardiac and all-cause mortality compared with controls with CKD and no AS ( P<0.001). Among patients with AS and CKD , there were 156 (19%) aortic valve replacements and 454 (54%) deaths (203 cardiac deaths) at 4.0±2.3 years of follow-up. Lower estimated glomerular filtration rate (hazard ratio per 10 mL/min per 1.73 m2: 1.18; 95% CI, 1.08-1.29) was associated with increased risk of all-cause mortality but not cardiac mortality (hazard ratio: 1.12; 95% CI, 0.97-1.30; P=0.13). Of patients undergoing aortic valve replacement, 61% had improvement in estimated glomerular filtration rate within 1 year (median percentage change=+2.8% per month). Conclusions Among patients with nondialysis CKD , AS is associated with significantly higher cardiac and all-cause mortality; lower estimated glomerular filtration rate is associated with increased mortality, and aortic valve replacement was associated with improved survival.

Investigation of association between bovine viral diarrhoea virus and cervid herpesvirus type-1, and abortion in New Zealand farmed deer

This study tested for association between bovine viral diarrhoea virus (BVDv) and cervid herpesvirus type-1 (CvHV-1) exposure and abortion in New Zealand farmed red deer. Rising two-year-old (R2, n = 22,130) and mixed-age (MA, n = 36,223) hinds from 87 and 71 herds, respectively, throughout New Zealand were pregnancy tested using ultrasound early in gestation (Scan-1) and 55-89 days later (Scan-2) to detect mid-term abortion. Sera from aborted and non-aborted hinds at Scan-2 were tested for BVDv and CvHV-1 using virus neutralisation tests. Available uteri from aborted hinds and from hinds not rearing a calf to weaning were tested by PCR for herpesvirus DNA. In herds with aborted hinds, 10.3% of 639 R2 and 17.2% of 302 MA hinds were sero-positive for BVDv and 18.6% of 613 R2 and 68.5% of 232 MA hinds were sero-positive for CvHV-1. There was no association between BVDv sero-status and abortion at animal level (R2 p = 0.36, MA p = 0.76) whereas CvHV-1 sero-positivity was negatively associated with abortion in MA hinds (p = 0.01) but not in R2 hinds (p = 0.36), MA). Eleven of 108 uteri from aborted R2 hinds but no MA hinds were positive for herpesvirus DNA. Vaginal samples from four R2 and one MA aborted hinds tested were negative for herpesvirus DNA. A Cervid Rhadinovirus type-2 (CRhV-2) was identified in seven PCR positive uteri samples. Findings suggest that BVDv and CvHV-1 may not be associated with abortion in R2 hinds, but association needs to be tested further in MA hinds. The role of CRhV-2 requires clarification.

Guideline-directed statin intensification in patients with new or worsening symptoms of peripheral artery disease

BACKGROUND

The ACC/AHA cholesterol guidelines recommend patients with peripheral artery disease (PAD) be treated with a moderate to high-intensity statin. The extent to which patients with new or worsening PAD symptoms are offered guideline therapy is unknown.

HYPOTHESIS

There is significant variability in rate of guideline-directed statin intensification across clinical practices.

METHODS

In the PORTRAIT registry, patterns of statin therapy were assessed in 1144 patients at 16 PAD specialty clinics between June 2011 and December 2015 before and after an evaluation for new or worsening claudication symptoms. We documented whether patients were treated with a guideline statin as well as the incidence of statin intensification. Statin intensification was defined as transitioning from no statin or low-intensity statin to moderate or high-intensity statin treatment. Patient factors associated with intensification were examined. Site and provider-level variation in intensification was summarized using an adjusted median odds ratio (aMOR).

RESULTS

Among 1144 patients, 810 (70.8%) were initially on guideline therapy compared to 334 (29.2%) that were not. In the latter, 103 (30.8%) received intensification following evaluation. Patients with typical symptoms displayed greater odds of intensification (OR 3.74; 95% CI: 1.23-11.41) while older patients had lower odds of intensification (OR 0.60/decade; 95% CI: 0.41-0.88). Site variability for statin intensification was observed across sites (aMOR = 3.15; 95% CI 1.22-9.60, [P = 0.02]) but not providers (aMOR = 1.89; 95% CI 1.00-3.90, [P = 0.14]).

CONCLUSIONS

Most patients evaluated at a PAD specialty clinic for new or worsening claudication symptoms arrived on guideline statin therapy. Only 31% not receiving appropriate therapy underwent statin intensification. These findings highlight an important opportunity to optimize medical therapy for patients with PAD.

Low Diastolic Blood Pressure Is Associated With Angina in Patients With Chronic Coronary Artery Disease

BACKGROUND

In patients with coronary artery disease (CAD), low diastolic blood pressure (DBP) is associated with increased risk of myocardial infarction, but its association with angina is unknown.

OBJECTIVES

The goal of this study was to examine the association of low DBP and angina in patients with CAD.

METHODS

The study assessed the frequency of angina (measured by using the Seattle Angina Questionnaire-Angina Frequency score) according to DBP in patients with known CAD from 25 U.S. cardiology clinics. Hierarchical logistic regression was used to test the association between DBP and angina, with a spline term for DBP to assess nonlinearity.

RESULTS

Among 1,259 outpatients with CAD, 411 (33%) reported angina in the prior month, with higher rates in the lowest DBP quartile (40 to 64 mm Hg: 37%). In the unadjusted model, DBP was associated with angina with a J-shaped relationship (p = 0.017, p for nonlinearity = 0.027), with a progressive increase in odds of angina as DBP decreased below ∼70 to 80 mm Hg. This association remained significant after sequential adjustment for demographic characteristics (p = 0.002), comorbidities (p = 0.002), heart rate (p = 0.002), systolic blood pressure (p = 0.046), and antihypertensive antianginal medications (p = 0.045).

CONCLUSIONS

In patients with chronic CAD, there seemed to be an association between lower DBP and increased odds of angina. If validated, these findings suggest that clinicians should consider less aggressive blood pressure control in patients with CAD and angina.

Preoperative dobutamine stress echocardiography in patients undergoing orthotopic liver transplantation

BACKGROUND

Coronary artery disease (CAD) is associated with increased mortality in patients who undergo orthotopic liver transplantation (OLT). Chronic vasodilatory state and poor exercise tolerance in patients with end-stage liver disease make dobutamine stress echocardiography (DSE) preferred for preoperative evaluation of CAD prior to OLT. We studied the incidence of positive DSE results and the association between DSE results and perioperative and longer-term events.

HYPOTHESIS

DSE results pre-OLT will predict short and long term outcomes.

METHODS

We studied 460 patients who underwent DSE within 1 year prior to OLT between 2004 and 2011. Primary events included death and MI at 30 days post-OLT. We also recorded longer-term deaths.

RESULTS

Four patients (0.9%) had an ischemic response to DSE, 360 (78%) were normal, and 96 (21%) were nondiagnostic. Fourteen patients (3%) had a primary event at 30 days following OLT (13 deaths and 1 NSTEMI), and there were 108 (24%) deaths at 4.6±2 years of follow-up. No patient with ischemia on DSE had a 30-day event. The accuracy, sensitivity, specificity, and positive and negative predictive values of DSE that was not normal (ie, ischemic or nondiagnostic response) to predict 30-day post-OLT events were 76%, 14%, 78%, 2%, and 97%, respectively. On Cox survival analysis, only baseline left ventricular ejection fraction (HR: 0.90, 95% CI: 0.85-0.96, P < 0.001) was associated with longer-term deaths.

CONCLUSIONS

Patients undergoing pre-OLT DSE have very low incidence of an ischemic response on DSE, and it has no association with 30-day events.

Validation of the Seattle angina questionnaire in women with ischemic heart disease

BACKGROUND

Although the Seattle Angina Questionnaire (SAQ) has been widely used to assess disease-specific health status in patients with ischemic heart disease, it was originally developed in a predominantly male population and its validity in women has been questioned.

METHODS

Using data from 8892 men and 4013 women across 2 multicenter trials and 5 registries, we assessed the construct validity, test-retest reliability, responsiveness to clinical change, and predictive validity of the SAQ Summary Score (SS) and its 5 subdomains (Physical Limitation (PL), Anginal Stability (AS), Angina Frequency (AF), Treatment Satisfaction (TS), and Quality of Life (QoL)) separately in men and women.

RESULTS

Comparable correlations of the SAQ SS with Canadian Cardiovascular Society class was demonstrated in both men and women (-0.48 for men, -0.46 for women). Similar correlations between the SAQ PL scale with treadmill exercise duration and Short Form-12 (SF-12) Physical Component Summary were observed in women and men (0.34-0.63 and 0.40-0.63, respectively). SAQ AS scores were significantly lower for both men and women with acute syndromes compared with 1 month later. The SAQ AF scale was strongly correlated with daily angina diaries (0.62 for men and 0.66 for women). The SAQ QoL scores were moderately correlated with the EQ5D visual analog scale and SF-12 general health question in men (0.43-0.50) and women (0.33-0.39). All SAQ scales demonstrated excellent reliability (intraclass correlation ≥0.78) in both men and women with stable CAD and were very sensitive to change after percutaneous coronary intervention (≥15-point difference in scores, standardized response mean ≥ 0.67). The SAQ SS was similarly predictive of 1-year mortality and cardiac re-hospitalizations for both men and women.

CONCLUSION

The SAQ demonstrates similar psychometric properties in men and women with CAD. These findings provide evidence for validity of the SAQ in assessing women with IHD.

Relation of Age and Health-Related Quality of Life to Invasive Versus Ischemia-Guided Management of Patients with Non-ST Elevation Myocardial Infarction

In older patients with non-ST-elevation myocardial infarction, an initial invasive strategy reduces cardiovascular events compared with an ischemia-guided approach; however its association with health status outcomes is unknown. Among patients with non-ST-elevation myocardial infarction from 2 multicenter US acute myocardial infarction (AMI) registries, health status was assessed at baseline and at 1, 6, and 12 months after AMI using the Seattle Angina Questionnaire (SAQ) and the 12-item Short-Form Health Survey (SF-12). Routine invasive management was defined as coronary angiography within 72 hours of admission without a preceding stress test. Among 3,559 patients with NSTEMI, 2,455 (69.0%) were treated with routine invasive treatment, which was more common in younger patients. In propensity-adjusted analyses, invasive treatment was associated with higher SAQ physical limitation, angina frequency, and summary scores over the year after AMI; however, the differences were small (<5 points, all p <0.05). Although there was a trend toward worse health status in patients aged ≥85 years treated with an initial invasive treatment, the interaction between age and treatment for any health status measure (all p ≥0.09) was not significant, except for SF-12 physical component score (p = 0.02), where worse scores were observed with invasive treatment in patients 85 years or older. In conclusion, an initial invasive treatment for patients with NSTEMI is associated with a small benefit in health status of marginal clinical significance, mainly in younger patients. The oldest old group trended toward less health status benefit from a routine invasive strategy-results that will need to be confirmed in a larger study.