Prospective deep learning-based quantitative assessment of coronary plaque by computed tomography angiography compared with intravascular ultrasound: the REVEALPLAQUE study.

AIMS: Coronary computed tomography angiography provides non-invasive assessment of coronary stenosis severity and flow impairment. Automated artificial intelligence (AI) analysis may assist in precise quantification and characterization of coronary atherosclerosis, enabling patient-specific risk determination and management strategies. This multicentre international study compared an automated deep learning-based method for segmenting coronary atherosclerosis in coronary computed tomography angiography (CCTA) against the reference standard of intravascular ultrasound (IVUS). METHODS AND RESULTS: The study included clinically stable patients with known coronary artery disease from 15 centres in the USA and Japan. An AI-enabled plaque analysis was utilized to quantify and characterize total plaque (TPV), vessel, lumen, calcified plaque (CP), non-calcified plaque (NCP), and low-attenuation plaque (LAP) volumes derived from CCTA and compared with IVUS measurements in a blinded, core laboratory-adjudicated fashion. In 237 patients, 432 lesions were assessed; mean lesion length was 24.5 mm, and mean IVUS-TPV was 186.0 mm3. AI-enabled plaque analysis on CCTA showed strong correlation and high accuracy when compared with IVUS; correlation coefficient, slope, and Y intercept for TPV were 0.91, 0.99, and 1.87, respectively; for CP volume 0.91, 1.05, and 5.32, respectively; and for NCP volume 0.87, 0.98, and 15.24, respectively. Bland-Altman analysis demonstrated strong agreement with little bias for these measurements. CONCLUSION: AI-enabled CCTA quantification and characterization of atherosclerosis demonstrated strong agreement with IVUS reference standard measurements. This tool may prove effective for accurate evaluation of coronary atherosclerotic burden and cardiovascular risk assessment.

Clinical Validation of a Machine-Learned, Point-of-Care System to IDENTIFY Functionally Significant Coronary Artery Disease.

Many clinical studies have shown wide performance variation in tests to identify coronary artery disease (CAD). Coronary computed tomography angiography (CCTA) has been identified as an effective rule-out test but is not widely available in the USA, particularly so in rural areas. Patients in rural areas are underserved in the healthcare system as compared to urban areas, rendering it a priority population to target with highly accessible diagnostics. We previously developed a machine-learned algorithm to identify the presence of CAD (defined by functional significance) in patients with symptoms without the use of radiation or stress. The algorithm requires 215 s temporally synchronized photoplethysmographic and orthogonal voltage gradient signals acquired at rest. The purpose of the present work is to validate the performance of the algorithm in a frozen state (i.e., no retraining) in a large, blinded dataset from the IDENTIFY trial. IDENTIFY is a multicenter, selectively blinded, non-randomized, prospective, repository study to acquire signals with paired metadata from subjects with symptoms indicative of CAD within seven days prior to either left heart catheterization or CCTA. The algorithm's sensitivity and specificity were validated using a set of unseen patient signals (n = 1816). Pre-specified endpoints were chosen to demonstrate a rule-out performance comparable to CCTA. The ROC-AUC in the validation set was 0.80 (95% CI: 0.78-0.82). This performance was maintained in both male and female subgroups. At the pre-specified cut point, the sensitivity was 0.85 (95% CI: 0.82-0.88), and the specificity was 0.58 (95% CI: 0.54-0.62), passing the pre-specified endpoints. Assuming a 4% disease prevalence, the NPV was 0.99. Algorithm performance is comparable to tertiary center testing using CCTA. Selection of a suitable cut-point results in the same sensitivity and specificity performance in females as in males. Therefore, a medical device embedding this algorithm may address an unmet need for a non-invasive, front-line point-of-care test for CAD (without any radiation or stress), thus offering significant benefits to the patient, physician, and healthcare system.

On-Treatment Platelet Reactivity and Ischemic Outcomes in Patients With Diabetes Mellitus: Two-Year Results From ADAPT-DES.

Background Diabetes mellitus and high platelet reactivity (HPR) on clopidogrel are both associated with increased risk of ischemic events after percutaneous coronary intervention, but whether the HPR-associated risk of adverse ischemic events differs by diabetes mellitus status is unknown. Methods and Results ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective, multicenter registry of patients treated with coronary drug-eluting stents. HPR was defined as P2Y12 reaction units >208 by the VerifyNow point-of-care assay. Cox multivariable analysis was used to assess whether HPR-associated risk of major adverse cardiac events (MACE; cardiac death, myocardial infarction, or stent thrombosis) varied for patients with insulin-treated diabetes mellitus (ITDM), non-ITDM, and no diabetes mellitus. Diabetes mellitus and HPR were included in an interaction analysis. Of 8582 patients enrolled, 2429 (28.3%) had diabetes mellitus, of whom 998 (41.1%) had ITDM. Mean P2Y12 reaction units were higher in patients with diabetes mellitus versus without diabetes mellitus, and HPR was more frequent in patients with diabetes mellitus. HPR was associated with consistently increased 2-year rates of MACE in patients with and without diabetes mellitus (Pinteraction=0.36). A significant interaction was present between HPR and non-insulin-treated diabetes mellitus versus ITDM for 2-year MACE (adjusted hazard ratio [HR] for non-ITDM, 2.28 [95% CI, 1.39-3.73] versus adjusted HR for ITDM, 1.02 [95% CI, 0.70-1.50]; Pinteraction=0.01). Conclusions HPR was more common in patients with diabetes mellitus and was associated with an increased risk of MACE in both patients with and without diabetes mellitus. In patients with diabetes mellitus, a more pronounced effect of HPR on MACE was present in lower-risk non-ITDM patients than in higher-risk patients with ITDM. Registration URL: https://clinicaltrials.gov/ct2/show/NCT00638794; Unique identifier: NCT00638794. ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents).

Multicenter validation of a machine learning phase space electro-mechanical pulse wave analysis to predict elevated left ventricular end diastolic pressure at the point-of-care.

BACKGROUND: Phase space is a mechanical systems approach and large-scale data representation of an object in 3-dimensional space. Whether such techniques can be applied to predict left ventricular pressures non-invasively and at the point-of-care is unknown. OBJECTIVE: This study prospectively validated a phase space machine-learned approach based on a novel electro-mechanical pulse wave method of data collection through orthogonal voltage gradient (OVG) and photoplethysmography (PPG) for the prediction of elevated left ventricular end diastolic pressure (LVEDP). METHODS: Consecutive outpatients across 15 US-based healthcare centers with symptoms suggestive of coronary artery disease were enrolled at the time of elective cardiac catheterization and underwent OVG and PPG data acquisition immediately prior to angiography with signals paired with LVEDP (IDENTIFY; NCT #03864081). The primary objective was to validate a ML algorithm for prediction of elevated LVEDP using a definition of ≥25 mmHg (study cohort) and normal LVEDP ≤ 12 mmHg (control cohort), using AUC as the measure of diagnostic accuracy. Secondary objectives included performance of the ML predictor in a propensity matched cohort (age and gender) and performance for an elevated LVEDP across a spectrum of comparative LVEDP (<12 through 24 at 1 mmHg increments). Features were extracted from the OVG and PPG datasets and were analyzed using machine-learning approaches. RESULTS: The study cohort consisted of 684 subjects stratified into three LVEDP categories, ≤12 mmHg (N = 258), LVEDP 13-24 mmHg (N = 347), and LVEDP ≥25 mmHg (N = 79). Testing of the ML predictor demonstrated an AUC of 0.81 (95% CI 0.76-0.86) for the prediction of an elevated LVEDP with a sensitivity of 82% and specificity of 68%, respectively. Among a propensity matched cohort (N = 79) the ML predictor demonstrated a similar result AUC 0.79 (95% CI: 0.72-0.8). Using a constant definition of elevated LVEDP and varying the lower threshold across LVEDP the ML predictor demonstrated and AUC ranging from 0.79-0.82. CONCLUSION: The phase space ML analysis provides a robust prediction for an elevated LVEDP at the point-of-care. These data suggest a potential role for an OVG and PPG derived electro-mechanical pulse wave strategy to determine if LVEDP is elevated in patients with symptoms suggestive of cardiac disease.

Identifying novel phenotypes of elevated left ventricular end diastolic pressure using hierarchical clustering of features derived from electromechanical waveform data.

Introduction: Elevated left ventricular end diastolic pressure (LVEDP) is a consequence of compromised left ventricular compliance and an important measure of myocardial dysfunction. An algorithm was developed to predict elevated LVEDP utilizing electro-mechanical (EM) waveform features. We examined the hierarchical clustering of selected features developed from these EM waveforms in order to identify important patient subgroups and assess their possible prognostic significance. Materials and methods: Patients presenting with cardiovascular symptoms (N = 396) underwent EM data collection and direct LVEDP measurement by left heart catheterization. LVEDP was classified as non-elevated ( ≤ 12 mmHg) or elevated (≥25 mmHg). The 30 most contributive features to the algorithm output were extracted from EM data and input to an unsupervised hierarchical clustering algorithm. The resultant dendrogram was divided into five clusters, and patient metadata overlaid. Results: The cluster with highest LVEDP (cluster 1) was most dissimilar from the lowest LVEDP cluster (cluster 5) in both clustering and with respect to clinical characteristics. In contrast to the cluster demonstrating the highest percentage of elevated LVEDP patients, the lowest was predominantly non-elevated LVEDP, younger, lower BMI, and males with a higher rate of significant coronary artery disease (CAD). The next adjacent cluster (cluster 2) to that of the highest LVEDP (cluster 1) had the second lowest LVEDP of all clusters. Cluster 2 differed from Cluster 1 primarily based on features extracted from the electrical data, and those that quantified predictability and variability of the signal. There was a low predictability and high variability in the highest LVEDP cluster 1, and the opposite in adjacent cluster 2. Conclusion: This analysis identified subgroups of patients with varying degrees of LVEDP elevation based on waveform features. An approach to stratify movement between clusters and possible progression of myocardial dysfunction may include changes in features that differentiate clusters; specifically, reductions in electrical signal predictability and increases in variability. Identification of phenotypes of myocardial dysfunction evidenced by elevated LVEDP and knowledge of factors promoting transition to clusters with higher levels of left ventricular filling pressures could permit early risk stratification and improve patient selection for novel therapeutic interventions.

Development and validation of a machine learned algorithm to IDENTIFY functionally significant coronary artery disease.

Introduction: Multiple trials have demonstrated broad performance ranges for tests attempting to detect coronary artery disease. The most common test, SPECT, requires capital-intensive equipment, the use of radionuclides, induction of stress, and time off work and/or travel. Presented here are the development and clinical validation of an office-based machine learned algorithm to identify functionally significant coronary artery disease without radiation, expensive equipment or induced patient stress. Materials and methods: The IDENTIFY trial (NCT03864081) is a prospective, multicenter, non-randomized, selectively blinded, repository study to collect acquired signals paired with subject meta-data, including outcomes, from subjects with symptoms of coronary artery disease. Time synchronized orthogonal voltage gradient and photoplethysmographic signals were collected for 230 seconds from recumbent subjects at rest within seven days of either left heart catheterization or coronary computed tomography angiography. Following machine learning on a proportion of these data (N = 2,522), a final algorithm was selected, along with a pre-specified cut point on the receiver operating characteristic curve for clinical validation. An unseen set of subject signals (N = 965) was used to validate the algorithm. Results: At the pre-specified cut point, the sensitivity for detecting functionally significant coronary artery disease was 0.73 (95% CI: 0.68-0.78), and the specificity was 0.68 (0.62-0.74). There exists a point on the receiver operating characteristic curve at which the negative predictive value is the same as coronary computed tomographic angiography, 0.99, assuming a disease incidence of 0.04, yielding sensitivity of 0.89 and specificity of 0.42. Selecting a point at which the positive predictive value is maximized, 0.12, yields sensitivity of 0.39 and specificity of 0.88. Conclusion: The performance of the machine learned algorithm presented here is comparable to common tertiary center testing for coronary artery disease. Employing multiple cut points on the receiver operating characteristic curve can yield the negative predictive value of coronary computed tomographic angiography and a positive predictive value approaching that of myocardial perfusion imaging. As such, a system employing this algorithm may address the need for a non-invasive, no radiation, no stress, front line test, and hence offer significant advantages to the patient, their physician, and healthcare system.

Antithrombotic strategy variability in atrial fibrillation and obstructive coronary disease revascularised with percutaneous coronary intervention: primary results from the AVIATOR 2 international registry.

BACKGROUND: Managing percutaneous coronary intervention (PCI) patients with atrial fibrillation (AF) presents challenges given that there are several potential antithrombotic therapy (ATT) strategies. AIMS: We examined ATT patterns, agreement between subjective physician ratings and validated risk scores, physician-patient perceptions influencing ATT and 1-year outcomes. METHODS: The AVIATOR 2 prospective registry enrolled 514 non-valvular AF-PCI patients from 11 sites. Treating physicians selected ATT and completed smartphone surveys rating stroke and bleeding risks, compared against CHA2DS2-VASc and HAS-BLED scores. Patients completed surveys regarding treatment understanding. Primary outcomes were 1-year major adverse cardiac or cerebrovascular events (MACCE: composite of death, myocardial infarction, definite/probable stent thrombosis, stroke, target lesion revascularisation) and actionable bleeding (Bleeding Academic Research Consortium 2, 3 or 5). RESULTS: The mean patient age was 73.2±9.0 years, including 25.8% females. Triple therapy (TT: 1 anticoagulant and 2 antiplatelet agents) was prescribed in 66.5%, dual antiplatelet therapy (DAPT) in 20.7% and dual therapy (1 anticoagulant+1 antiplatelet agent) in 12.8% of patients. Physician ratings and validated risk scores showed poor agreement (stroke: kappa=0.03; bleeding: kappa=0.07). Physicians rated bleeding-related safety (93.8%) as the main factor affecting ATT choice. Patients worried about stroke over bleeding (50.6% vs 14.8%). No group differences by ATT strategy were observed in 1-year MACCE (TT 14.1% vs dual therapy 12.7% vs DAPT 18.5%; p=0.25), or actionable bleeding (14.7% vs 7.9% vs 15.1%, respectively; p=0.89). CONCLUSIONS: The AVIATOR 2 study is the first digital health study examining physician-patient perspectives on ATT choices after AF-PCI. TT was the most common strategy without differences in 1-year outcomes in ATT strategy. Physicians rated safety first when prescribing ATT; patients feared stroke over bleeding. CLINICALTRIALS: gov: NCT02362659.

Dual Antiplatelet Therapy Discontinuation, Platelet Reactivity, and Adverse Outcomes After Successful Percutaneous Coronary Intervention.

OBJECTIVES: The purpose of this study was to assess the extent to which the association between premature dual antiplatelet therapy (DAPT) discontinuation and excess risk of thrombotic events varies according to the reason and timing of DAPT discontinuation and whether high on-treatment platelet reactivity (HPR) influences the risk of thrombotic events after premature DAPT discontinuation. BACKGROUND: DAPT after percutaneous coronary intervention (PCI) suppresses platelet reactivity, and HPR on clopidogrel after PCI is associated with an increased risk of thrombotic events. METHODS: ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective, multicenter registry of 8,582 patients successfully treated with coronary drug-eluting stents that assessed HPR on clopidogrel. For patients who discontinued aspirin or clopidogrel at any time during the study, the reasons for discontinuation were systematically categorized. RESULTS: Planned DAPT discontinuation occurred within 2 years in 3,203 (37.3%) patients. One thousand four hundred eighteen (16.5%) patients discontinued DAPT for unplanned reasons, including surgery or trauma (n = 768 [8.9%]), patient nonadherence (n = 321 [3.7%]), bleeding complications (n = 264 [3.1%]), and drug allergy or hypersensitivity (n = 113 [1.3%]). Unplanned but not planned DAPT discontinuation was associated with an increased risk of a major adverse cardiac event (MACE, defined as the composite of cardiac death, myocardial infarction, or stent thrombosis); with highest risk within 3 months after PCI (adjusted HR: 7.65, 95% CI: 2.77-21.10 vs adjusted HR: 2.47, 95% CI: 1.70-3.58 for unplanned DAPT discontinuation ≥3 weeks after PCI). MACE risk after DAPT discontinuation was not moderated by HPR (Pinteraction = 0.91). CONCLUSIONS: In this large-scale all-comers registry, premature DAPT discontinuation for unplanned reasons occurred in approximately 1 of 6 patients after DES implantation and was associated with a markedly increased risk of MACEs. (Assessment of Dual AntiPlatelet Therapy With Drug Eluting Stents [ADAPT-DES]; NCT00638794).

Long-Term Clinical Impact of Contrast-Associated Acute Kidney Injury Following PCI: An ADAPT-DES Substudy.

OBJECTIVES: This study sought to determine correlates and consequences of contrast-associated acute kidney injury (CA-AKI) on clinical outcomes in patients with or without pre-existing chronic kidney disease (CKD). BACKGROUND: The incidence and impact of CA-AKI on clinical outcomes during contemporary percutaneous coronary intervention (PCI) are not fully defined. METHODS: The ADAPT-DES (Assessment of Dual AntiPlatelet Therapy With Drug Eluting Stents) study was a prospective, multicenter registry of 8,582 patients treated with ≥1 drug-eluting stent(s). CA-AKI was defined as a post-PCI increase in serum creatinine of >0.5 mg/dL or a relative increase of ≥25% compared with pre-PCI. CKD was defined as estimated glomerular filtration rate <60 mL/min/1.73 m2. The primary endpoint was the 2-year rate of net adverse clinical events (NACE): All-cause mortality, myocardial infarction (MI), definite or probable stent thrombosis, or major bleeding. RESULTS: Of 7287 (85%) patients with evaluable data, 476 (6.5%) developed CA-AKI. In a multivariable model, older age, female sex, Caucasian race, congestive heart failure, diabetes, hypertension, CKD, presentation with ST-segment elevation MI, Killip class II to IV, radial access, intra-aortic balloon pump use, hypotension, and number of stents were independent predictors of CA-AKI. The 2-year NACE rate was higher in patients with CA-AKI (adjusted HR: 1.88; 95% CI: 1.42-2.49), as was each component of NACE (all-cause mortality, HR: 1.77; 95% CI: 1.22-2.55; MI, HR: 1.67; 95% CI: 1.18-2.36; definite/probable stent thrombosis, HR: 1.71; 95% CI: 1.10-2.65; and major bleeding, HR: 1.38; 95% CI: 1.06-1.80). Compared with the CA-AKI-/CKD- group, the CA-AKI+/CKD- (HR: 1.83; 95% CI: 1.33-2.52), CA-AKI-/CKD+ (HR: 1.56; 95% CI: 1.15-2.13), CA-AKI+/CKD+ (HR: 3.29; 95% CI: 1.92-5.67), and maintenance dialysis (HR: 2.67; 95% CI: 1.65-4.31) groups were at higher risk of NACE. CONCLUSIONS: CA-AKI was relatively common after contemporary PCI and was associated with increased 2-year rates of NACE. Patients with pre-existing CKD were at particularly high risk for NACE after CA-AKI.

Stent Expansion Indexes to Predict Clinical Outcomes: An IVUS Substudy From ADAPT-DES.

OBJECTIVES: The aim of this study was to evaluate various stent expansion indexes to determine the best predictor of clinical outcomes. BACKGROUND: Numerous intravascular ultrasound (IVUS) studies have shown minimum stent area (MSA) to be the most powerful predictor of future events. METHODS: ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective, multicenter registry of 8,582 patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stents. Native coronary artery lesions treated with IVUS-guided PCI with final analyzable IVUS were included. Ten stent expansion indexes (MSA, MSA/vessel area at MSA site, conventional stent expansion [MSA/average of proximal and distal reference luminal area], minimum stent expansion using Huo-Kassab or linear model accounting for vessel tapering, stent asymmetry [minimum/maximum stent diameter within the entire stent], stent eccentricity [smallest minimum/maximum stent diameter at a single slice within the stent], IVUS-XPL [Impact of intravascular Ultrasound Guidance on Outcomes of Xience Prime Stents in Long Lesions] criteria, ULTIMATE [Intravascular Ultrasound Guided Drug Eluting Stents Implantation in "All-Comers" Coronary Lesions] criteria, and ILUMIEN IV criteria) were evaluated for their associations with lesion-specific 2-year clinically driven target lesion revascularization (TLR) or definite stent thrombosis. RESULTS: Overall, 2,140 lesions in 1,831 patients were included; final MSA measured 6.2 ± 2.4 mm2. Among the 10 stent expansion indexes, only MSA/vessel area at the MSA site was independently associated with 2-year clinically driven TLR or definite stent thrombosis (hazard ratio: 0.77; 95% confidence interval: 0.59-0.99; P = 0.04) after adjusting for morphologic and procedural parameters. CONCLUSIONS: In this IVUS-guided PCI cohort with excellent final MSA overall, stent/vessel area at the MSA site, an index of relative stent expansion, was superior to absolute MSA and other expansion indexes in predicting 2-year clinically driven TLR or definite stent thrombosis.

Stent Thrombosis Risk Over Time on the Basis of Clinical Presentation and Platelet Reactivity: Analysis From ADAPT-DES.

OBJECTIVES: The aim of this study was to determine the risk period for increased stent thrombosis (ST) after percutaneous coronary intervention (PCI) in patients with acute coronary syndromes (ACS) and whether this increased risk is related to high platelet reactivity (HPR). BACKGROUND: ST risk after PCI is higher among patients with ACS than those with stable ischemic heart disease. When ST risk is highest in patients with ACS and how that is affected by HPR is unknown. METHODS: Using the ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) registry, ST rates during 2-year follow-up post-PCI with drug-eluting stents were compared among patients presenting with ACS (myocardial infarction [MI] or unstable angina) or stable ischemic heart disease (non-ACS). Landmark analyses were done at 30 days and 1 year post-PCI. Platelet reactivity on aspirin and clopidogrel post-PCI was assessed using VerifyNow assays. RESULTS: Of 8,582 patients, 2,063 presented with MI, 2,370 with unstable angina, and 4,149 with non-ACS. Incidence rates of HPR were 48.0%, 43.3%, and 39.8%, respectively (p < 0.001). Within the first 30 days post-PCI, patients presenting with MI had increased ST risk compared with patients with non-ACS (hazard ratio [HR]: 4.52; 95% confidence interval [CI]: 2.01 to 10.14; p < 0.001). After 30 days, relative ST risks were progressively lower and no longer significant between groups (31 days to 1 year post-PCI: HR: 1.97; 95% CI: 0.80 to 4.85; >1 year post-PCI: HR: 0.89; 95% CI: 0.27 to 2.92). The elevated ST risk in patients with MI within 30 days was largely confined to those with HPR on clopidogrel (HR: 5.77; 95% CI: 2.13 to 15.63; p < 0.001). CONCLUSIONS: Among patients undergoing PCI, rates of ST during 2-year follow-up were highest in those with MI and lowest in those with non-ACS. Increased ST risk in patients with MI was greatest in the first 30 days post-PCI and was observed predominantly among those with increased HPR on clopidogrel. These findings emphasize the importance of adequate P2Y12 inhibition after MI, especially within the first 30 days after stent implantation.

Impact of high on-treatment platelet reactivity on outcomes following PCI in patients on hemodialysis: An ADAPT-DES substudy.

OBJECTIVES: We sought to compare clinical outcomes after percutaneous coronary intervention (PCI) in patients on versus not on hemodialysis (HD) and examine whether high on-treatment platelet reactivity (HPR) further impacts outcomes among patients on HD. BACKGROUND: Both chronic kidney disease (CKD) and HPR are predictors of major adverse cardiac events (MACE) after PCI. METHODS: Two-year outcomes of patients from the prospective, multicenter ADAPT-DES study (N = 8,582) were analyzed according to HD status at enrollment. All patients underwent platelet function testing with the VerifyNow assay; HPR on clopidogrel was defined as P2Y12 reaction units (PRU) >208. RESULTS: Compared with non-HD patients, patients on HD (n = 85) had significantly higher baseline PRU (median 254 vs. 188, p = .001) and more frequently had HPR (61.7% vs. 42.5%, p < .001). HD was associated with increased 2-year rates of MACE (death, myocardial infarction (MI) or definite stent thrombosis (ST); 23.4% vs. 10.7%, p < .001). HD was also strongly associated with 2-year overall mortality, cardiac death, MI, target vessel revascularization, major bleeding, stroke and ST. Following adjustment for HPR and other covariates, HD was independently associated with overall mortality, MI, ST, and major bleeding at 2 years. The relationship between HD status and 2-year MACE was consistent in patients with and without HPR (Pinteraction = .78). CONCLUSIONS: Nearly two-thirds of patients on HD exhibited HPR on clopidogrel, and both HD and HPR were independently associated with 2-year adverse outcomes after DES implantation. However, the deleterious impact of HD on clinical outcomes was present in both patients with and without HPR.

Impact of Smoking on Platelet Reactivity and Clinical Outcomes After Percutaneous Coronary Intervention: Findings From the ADAPT-DES Study.

BACKGROUND: Smoking is a potent risk factor for coronary artery disease; however, prior studies describe increased platelet inhibition with clopidogrel among smokers, and some studies report improved outcomes among smokers, a finding described as the smoker's paradox. This study assessed the relationship between platelet reactivity and clinical outcomes after percutaneous coronary interventions among current smokers and nonsmokers. METHODS: ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective, multicenter registry of patients treated with coronary drug-eluting stents. Platelet reactivity was assessed by the VerifyNow point-of-care assay; high on-treatment platelet reactivity (HPR) was defined as P2Y12 reaction units >208. A propensity-adjusted multivariable analysis was performed to determine the relationship between current smoking, platelet reactivity, and subsequent adverse events. RESULTS: Among 8582 patients, 22.6% were active smokers at the time of their percutaneous coronary intervention procedure. Current smokers were younger and had fewer comorbidities compared with nonsmokers. Current smokers had lower mean P2Y12 reaction units and lower rates of HPR compared with nonsmokers. Current smokers had similar rates of adverse events compared with nonsmokers. HPR was associated with higher rates of adverse events for both smokers and nonsmokers; however, there was evidence of interaction between smoking status and the effect of HPR. Smokers with HPR had significantly higher rates of stent thrombosis. Adverse event rates were highest among current smokers with HPR. CONCLUSIONS: Current smoking was associated with lower P2Y12 reaction units and lower rates of HPR on average; however, the combination of current smoking and HPR was associated with high rates of stent thrombosis. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00638794.

Association Between Hypertension, Platelet Reactivity, and the Risk of Adverse Events After Percutaneous Coronary Intervention (From the ADAPT-DES Study).

Hypertension is associated with vascular and endothelial dysfunction that may result in a greater propensity for reactive platelets to cause thrombosis. We sought to assess whether the risk of major adverse cardiac events (MACE) after percutaneous coronary intervention (PCI) in patients with on-clopidogrel residual high platelet reactivity (HPR) varies in patients with versus without hypertension. Assessment of dual antiplatelet therapy with drug eluting stents (ADAPT-DES) was a prospective, multicenter registry of patients successfully treated with coronary drug-eluting stents (DES). HPR was defined as P2Y12 reaction units (PRU) >208, as assessed by the VerifyNow point-of-care assay. Multivariable Cox proportional hazards regression was used to assess whether the adjusted association between HPR and 2-year risk of MACE (cardiac death, myocardial infarction [MI], or stent thrombosis) was different in patients with versus without hypertension. A total of 6833 of 8582 patients (79.6%) had a history of hypertension. Patients with compared with those without hypertension were older, more likely to have other cardiovascular risk factors, and had higher PRU (190.1 ± 97.3 vs 179.5 ± 94.3; p <0.0001). Patients with hypertension had significantly higher 2-year rates of MACE (7.0% vs 4.4%, p <0.001), all-cause death (4.2% vs 2.5%, p = 0.001), and MI (5.2% vs 3.2%, p <0.001), and had nominally higher rates of stent thrombosis (1.0% vs 0.5%, p = 0.059). A significant interaction was present between hypertension and HPR regarding 2-year MACE risk (adjusted hazard ratio for HPR vs no HPR 1.38, 95% confidence interval 1.14 to 1.68 for patients with hypertension vs 0.81, 95% confidence interval 0.50 to 1.33 for patients without hypertension, p = 0.046). In conclusion, following successful PCI with DES, 2-year MACE rates are increased in patients with both hypertension and residual HPR on clopidogrel. HPR had a greater effect on the risk of adverse events among patients with versus without hypertension.

Relationship Between Stent Diameter, Platelet Reactivity, and Thrombotic Events After Percutaneous Coronary Artery Revascularization.

Small vessel diameter and residual platelet reactivity are independent predictors of thrombotic events after percutaneous coronary intervention (PCI). We sought to determine whether an interaction exists between residual platelet reactivity and stent diameter regarding the occurrence of stent thrombosis and other adverse events after PCI. We stratified patients in the prospective ADAPT-DES registry who underwent single-lesion PCI according to if they received a small diameter stent (SDS, defined as a stent with a diameter of 2.25 mm). Patients receiving an SDS were compared with patients receiving a stent ≥2.5 mm using Kaplan-Meier rates and multivariable Cox proportional hazards regression. We defined major adverse cardiac events (MACE) as the composite of cardiac death, myocardial infarction, and stent thrombosis (ST). Among 5,608 patients who underwent single-lesion PCI in ADAPT-DES, 222 (4.0%) patients received an SDS. Patients with an SDS were more likely than patients without an SDS to have 3-vessel disease but received, on average, fewer stents and were less likely to present with a thrombotic lesion. Receiving versus not receiving an SDS was associated with increased risk of ST (adjusted hazard ratio 4.35, 95% confidence interval 1.95 to 9.73, p <0.001) as well as MACE (adjusted hazard ratio 1.75, 95% confidence interval 1.11 to 2.75, p = 0.02). There was no statistical interaction between platelet reactivity and SDS regarding ST (p = 0.12) or MACE (p = 0.51). In conclusion, PCI with small drug-eluting stents is associated with a high risk of thrombotic events, including ST. Further studies should explore whether alternative treatment strategies are appropriate in small vessels.

Geographical Variations in Patterns of DAPT Cessation and Two-Year PCI Outcomes: Insights from the PARIS Registry.

BACKGROUND: Data on geographical variations in dual antiplatelet therapy (DAPT) cessation and the impact on outcomes after percutaneous coronary intervention (PCI) are limited. We sought to evaluate geographical patterns of DAPT cessation and associated outcomes in patients undergoing PCI in the United States versus Europe. METHODS: Analyzing data from the PARIS registry, we studied 3,660 U.S. patients (72.9%) and 1,358 European patients (27.1%) that underwent PCI with stent implantation. DAPT cessation was classified as physician-recommended discontinuation, interruption (< 14 days), or disruption due to bleeding or noncompliance. The primary endpoint was 2-year major adverse cardiovascular events (MACE) defined as a composite of cardiac death, stent thrombosis, myocardial infarction, or target lesion revascularization. RESULTS: Cardiovascular risk factors were more common in the United States, whereas procedural complexity was greater in Europe. The incidence of 2-year DAPT discontinuation was significantly lower in U.S. versus European patients (30.7% vs. 65.6%; p < 0.001); however, rates of interruption (13.7% vs. 1.5%, p < 0.001) and disruption (17.7% vs. 5.1%, p < 0.001) were higher. DAPT discontinuation was associated with lower adjusted risk, whereas DAPT disruption was associated with greater risk for 2-year MACE, without interaction by region. After adjustment for baseline characteristics and DAPT cessation, 2-year MACE risk was not statistically different between regions (10.3% for Europe vs. 11.9% for U.S., adjusted hazard ratio 0.81, 95% confidence interval 0.65-1.01, p = 0.065). CONCLUSION: DAPT cessation patterns, along with clinical and angiographic risk, vary substantially between PCI patients in the U.S. versus Europe. Despite such differences, cardiovascular risk associated with DAPT cessation remains uniform.

Adverse events in patients with high platelet reactivity following successful chronic total occlusion PCI: The Assessment of Dual AntiPlatelet Therapy with Drug-Eluting Stents (ADAPT-DES) study.

BACKGROUND: Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) typically requires a greater number of stents and longer stent length than non-CTO PCI, placing these patients at greater risk for adverse ischemic events. We sought to determine whether the association between high platelet reactivity (HPR) and the risk of ischemic events is stronger after CTO than non-CTO PCI. METHODS: Patients undergoing successful PCI in the multicenter ADAPT-DES study were stratified according to whether they underwent PCI of a CTO. HPR was defined as VerifyNow platelet reaction units >208. The study primary endpoint was the 2-year risk target vessel failure ([TVF] defined as cardiac death, myocardial infarction, or target lesion revascularization). RESULTS: CTO PCI was performed in 400 of 8448 patients. HPR was present in 34.5% of CTO PCI patients and 43.1% of non-CTO PCI patients (P = .0007). Patients undergoing CTO PCI with versus without HPR had significantly higher 2-year rates of TVF (15.0% versus 8.3%, P = .04) without significant differences in bleeding. HPR was an independent predictor of 2-year TVF (adjusted HR 1.16, 95% CI 1.02-1.34, P = .03) whereas CTO PCI was not (adjusted HR 0.89, 95% CI 0.65-1.22, P = .48). There was a significant interaction between CTO versus non-CTO PCI and PRU as a continuous variable for 2-year TVF (Pinteraction = 0.02). CONCLUSIONS: In ADAPT-DES, HPR was associated with an increased 2-year risk of TVF after PCI, an association that was at least as strong after CTO PCI compared with non-CTO PCI.

Impact of Point-of-Care Platelet Function Testing Among Patients With and Without Acute Coronary Syndromes Undergoing Percutaneous Coronary Intervention With Drug-Eluting Stents (from the ADAPT-DES Study).

We sought to examine if the risk conferred by high on-treatment platelet reactivity (HPR) varies based upon clinical presentation. We examined the relation between HPR (P2Y12 reaction units >208) and adverse ischemic and bleeding events among patients with and without acute coronary syndromes (ACS) from ADAPT-DES; 51.7% of patients had ACS. After clopidogrel loading, ACS patients had higher P2Y12 reaction units and a greater prevalence of HPR based on VerifyNow P2Y12 assay. Of 92 definite or probable stent thrombosis (ST) events at 2 years, 65.2% occurred among patients with ACS. HPR was independently associated with ST in ACS patients (adjusted hazard ratio 2.29, 95% confidence interval 1.32 to 3.98) but not with clinically relevant bleeding. Although no statistical interactions between ACS status and these associations were observed, non-ACS patients exhibited an attenuated association between HPR and ST, and an inverse association between HPR and clinically relevant bleeding. HPR was similarly associated with myocardial infarction, but not with overall mortality in ACS and non-ACS patients. In conclusion, the majority of ST events in the 2 years after drug-eluting stent placement occurred in ACS patients; HPR was strongly associated with ST in these patients. These data support current recommendations for using more potent antiplatelet therapies in ACS patients.

Relationship Between Intravascular Ultrasound Guidance and Clinical Outcomes After Drug-Eluting Stents.

Background In the large-scale ADAPT-DES study (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents), drug-eluting stent implantation with intravascular ultrasound (IVUS) guidance was associated with a reduction in 1-year rates of stent thrombosis, myocardial infarction (MI), and major adverse cardiac events (cardiac death, MI, or stent thrombosis) compared with angiography guidance alone. We assessed whether the benefits of IVUS guidance were maintained, reduced, or increased at 2 years. Methods and Results ADAPT-DES was a prospective, multicenter, nonrandomized all-comers study of 8582 consecutive patients at 11 US and German sites designed to determine the frequency, timing, and correlates of adverse events after drug-eluting stents. Propensity-adjusted multivariable analysis was performed to examine the impact of IVUS guidance on 2-year outcomes. IVUS guidance (n=3361; 39%) compared with angiography guidance (n=5221; 61%) was associated with reduced 2-year adjudicated rates of (1) major adverse cardiac events (cardiac death, MI, or stent thrombosis; 4.9% versus 7.5%; adjusted hazard ratio, 0.72; 95% CI, 0.59-0.89; P=0.003), (2) definite/probable stent thrombosis (0.55% versus 1.16%; adjusted hazard ratio, 0.40; 95% CI, 0.22-0.73; P=0.003), and (3) MI (3.5% versus 5.6%; adjusted hazard ratio, 0.65; 95% CI, 0.51-0.83; P=0.0006). By landmark analysis, IVUS guidance compared with angiography guidance was also associated with significantly reduced rates of major adverse cardiac events, MI, stent thrombosis, and clinically driven target lesion revascularization between 1 and 2 years after drug-eluting stent implantation. The number needed to treat with IVUS guidance to prevent 1 major adverse cardiac event was reduced from 64 (42-137) at 1 year to 41 (29-69) at 2 years. Conclusions In ADAPT-DES, the early improvement in event-free survival after drug-eluting stent implantation with IVUS guidance compared with angiography guidance was further increased with longer term follow-up to 2 years. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT00638794.