Validation of a machine learned model to predict the diagnosis of myocardial infarction

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
D Doudesis ◽  
J Yang ◽  
A Tsanas ◽  
C Stables ◽  
A Shah ◽  
...  

Abstract Introduction The myocardial-ischemic-injury-index (MI3) is a promising machine learned algorithm that predicts the likelihood of myocardial infarction in patients with suspected acute coronary syndrome. Whether this algorithm performs well in unselected patients or predicts recurrent events is unknown. Methods In an observational analysis from a multi-centre randomised trial, we included all patients with suspected acute coronary syndrome and serial high-sensitivity cardiac troponin I measurements without ST-segment elevation myocardial infarction. Using gradient boosting, MI3 incorporates age, sex, and two troponin measurements to compute a value (0–100) reflecting an individual's likelihood of myocardial infarction, and estimates the negative predictive value (NPV) and positive predictive value (PPV). Model performance for an index diagnosis of myocardial infarction, and for subsequent myocardial infarction or cardiovascular death at one year was determined using previously defined low- and high-probability thresholds (1.6 and 49.7, respectively). Results In total 20,761 of 48,282 (43%) patients (64±16 years, 46% women) were eligible of whom 3,278 (15.8%) had myocardial infarction. MI3 was well discriminated with an area under the receiver-operating-characteristic curve of 0.949 (95% confidence interval 0.946–0.952) identifying 12,983 (62.5%) patients as low-probability (sensitivity 99.3% [99.0–99.6%], NPV 99.8% [99.8–99.9%]), and 2,961 (14.3%) as high-probability (specificity 95.0% [94.7–95.3%], PPV 70.4% [69–71.9%]). At one year, subsequent myocardial infarction or cardiovascular death occurred more often in high-probability compared to low-probability patients (17.6% [520/2,961] versus 1.5% [197/12,983], P<0.001). Conclusions In unselected consecutive patients with suspected acute coronary syndrome, the MI3 algorithm accurately estimates the likelihood of myocardial infarction and predicts probability of subsequent adverse cardiovascular events. Performance of MI3 at example thresholds Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Medical Research Council

2018 ◽  
Vol 8 (5) ◽  
pp. 421-431 ◽  
Author(s):  
Pei Gee Chew ◽  
Fredrick Frost ◽  
Liam Mullen ◽  
Michael Fisher ◽  
Heidar Zadeh ◽  
...  

Background: We tested the hypothesis that a single high sensitivity troponin at limits of detection (LOD HSTnT) (<5 ng/l) combined with a presentation non-ischaemic electrocardiogram is superior to low-risk Global Registry of Acute Coronary Events (GRACE) (<75), Thrombolysis in Myocardial Infarction (TIMI) (≤1) and History, ECG, Age, Risk factors and Troponin (HEART) score (≤3) as an aid to early, safe discharge for suspected acute coronary syndrome. Methods: In a prospective cohort study, risk scores were computed in consecutive patients with suspected acute coronary syndrome presenting to the Emergency Room of a large English hospital. Adjudication of myocardial infarction, as per third universal definition, involved a two-physician, blinded, independent review of all biomarker positive chest pain re-presentations to any national hospital. The primary and secondary outcome was a composite of type 1 myocardial infarction, unplanned coronary revascularisation and all cause death (MACE) at six weeks and one year. Results: Of 3054 consecutive presentations with chest pain 1642 had suspected acute coronary syndrome (52% male, median age 59 years, 14% diabetic, 20% previous myocardial infarction). Median time from chest pain to presentation was 9.7 h. Re-presentations occurred in eight hospitals with 100% follow-up achieved. Two hundred and eleven (12.9%) and 279 (17%) were adjudicated to suffer MACE at six weeks and one year respectively. Only HEART ≤3 (negative predictive value MACE 99.4%, sensitivity 97.6%, %discharge 53.4) and LOD HSTnT strategy (negative predictive value MACE 99.8%, sensitivity 99.5%, %discharge 36.9) achieved pre-specified negative predictive value of >99% for MACE at six weeks. For type 1 myocardial infarction alone the negative predictive values at six weeks and one year were identical, for both HEART ≤3 and LOD HSTnT at 99.8% and 99.5% respectively. Conclusion: HEART ≤3 or LOD HSTnT strategy rules out short and medium term myocardial infarction with ≥99.5% certainty, and short-term MACE with >99% certainty, allowing for early discharge of 53.4% and 36.9% respectively of suspected acute coronary syndrome. Adoption of either strategy has the potential to greatly reduce Emergency Room pressures and minimise follow-up investigations. Very early presenters (<3 h), due to limited numbers, are excluded from these conclusions.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J.F Iglesias ◽  
D Heg ◽  
M Roffi ◽  
D Tueller ◽  
O Muller ◽  
...  

Abstract Background Newest generation drug-eluting stents (DES) combining ultrathin cobalt chromium platforms with biodegradable polymers may reduce target lesion failure (TLF) as compared to second generation DES among patients with acute coronary syndrome (ACS). While previous studies indicated a potential benefit within the first two years after percutaneous coronary intervention (PCI), it remains uncertain whether the clinical benefit persists after complete degradation of the polymer coating. Purpose To compare the long-term effects of ultrathin-strut biodegradable polymer sirolimus-eluting stents (BP-SES) versus thin-strut durable polymer everolimus-eluting stents (DP-EES) for PCI in patients with ACS. Methods We performed a subgroup analysis of ACS patients included into the BIOSCIENCE trial (NCT01443104), a randomized trial comparing BP-SES with DP-EES. The primary endpoint of the present post-hoc analysis was TLF, a composite of cardiac death, target vessel myocardial infarction (MI) and clinically indicated target lesion revascularization (TLR), at 5 years. Results Among 2,119 patients enrolled between March 2012 and May 2013, 1,131 (53%) presented with ACS (ST-segment elevation myocardial infarction, 36%). Compared to patients with stable CAD, ACS patients were younger, had a lower baseline cardiac risk profile, including a lower prevalence of hypertension, hypercholesterolaemia, diabetes mellitus, and peripheral artery disease, and had a greater incidence of previous revascularization procedures. At 5 years, TLF occurred similarly in 89 patients (cumulative incidence, 16.9%) treated with BP-SES and 85 patients (16.0%) treated with DP-EES (RR 1.04; 95% CI 0.78–1.41; p=0.78) in patients with ACS, and in 109 patients (24.1%) treated with BP-SES and 104 patients (21.8%) treated with DP-EES (RR 1.11; 95% CI 0.85–1.45; p=0.46) in stable CAD patients (p for interaction=0.77) (Figure 1, Panel A). Cumulative incidences of cardiac death (8% vs. 7%; p=0.66), target vessel MI (5.2% vs. 5.8%; p=0.66), clinically indicated TLR (8.9% vs. 8.3%; p=0.63) (Figure 1, Panel B-D), and definite thrombosis (1.4% vs. 1.0%; p=0.57) at 5 years were similar among ACS patients treated with ultrathin-strut BP-SES or thin-strut DP-EES. Overall, there was no interaction between clinical presentation and treatment effect of BP-SES versus DP-EES. Conclusion In a subgroup analysis of the BIOSCIENCE trial, we found no difference in long-term clinical outcomes between ACS patients treated with ultrathin-strut BP-SES or thin-strut DP-EES at five years. Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Unrestricted research grant to the institution from Biotronik AG, Switzerland


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Bularga ◽  
A Anand ◽  
F.E Strachan ◽  
K.K Lee ◽  
S Stewart ◽  
...  

Abstract Background Type 2 myocardial infarction is common and associated with substantial risk of adverse clinical outcomes, worse than type 1 myocardial infarction, with as few as 30% of patients still alive at five years. However, this broad diagnostic term encompasses multiple mechanisms of supply-demand imbalance, which may be associated with different risks of adverse outcomes. Purpose We aimed to assess the prevalence and clinical outcomes of different mechanisms of supply-demand imbalance related to survival in the High-STEACS (High-Sensitivity Troponin in the Evaluation of patients with Acute Coronary Syndrome) randomised controlled trial. Methods The High-STEACS trial was a stepped wedge cluster randomised controlled trial in ten hospitals across Scotland, including 48,282 consecutive patients with suspected acute coronary syndrome. The diagnosis was adjudicated according to the Fourth Universal Definition of Myocardial Infarction. In patients with type 2 myocardial infarction, we prospectively adjudicated the cause for supply demand imbalance. Linkage of electronic healthcare records was used to track investigation, treatments and clinical outcomes. We used the Kaplan-Meier method, the log rank test and cox regression models adjusted for age, sex, renal function and co-morbidities to evaluate the risk of future all-cause mortality between categories. Results We identified 1,121 patients with type 2 myocardial infarction (age 74- ± 14, 55% female). At one year, death from any cause occurred in 23% (258/1,121) of patients. The most common reason for supply-demand imbalance was tachyarrhythmia in 55% (616/1,121), followed by hypoxaemia in 20% (219/1,121) of patients. Tachyarrhythmia was associated with reduced future risk of all-cause mortality (adjusted HR 0.69, 95% CI 0.43–1.09), similar to those with type 1 myocardial infarction. Comparatively, patients with hypoxaemia appeared at highest risk (adjusted HR 1.75, 95% CI 1.09–2.80). Conclusion The mechanism of myocardial oxygen supply-demand imbalance is associated with future prognosis, and should be considered when risk stratifying patients with type 2 myocardial infarction. Supply-demand imbalance survival Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): British Heart Foundation


2019 ◽  
Vol 27 (7) ◽  
pp. 696-705 ◽  
Author(s):  
Fabrizio D'Ascenzo ◽  
Maurizio Bertaina ◽  
Francesco Fioravanti ◽  
Federica Bongiovanni ◽  
Sergio Raposeiras-Roubin ◽  
...  

Introduction The benefits of short versus long-term dual antiplatelet therapy (DAPT) based on the third generation P2Y12 antagonists prasugrel or ticagrelor, in patients with acute coronary syndromes treated with percutaneous coronary intervention remain to be clearly defined due to current evidences limited to patients treated with clopidogrel. Methods All acute coronary syndrome patients from the REgistry of New Antiplatelets in patients with Myocardial Infarction (RENAMI) undergoing percutaneous coronary intervention and treated with aspirin, prasugrel or ticagrelor were stratified according to DAPT duration, that is, shorter than 12 months (D1 group), 12 months (D2 group) and longer than 12 months (D3 group). The three groups were compared before and after propensity score matching. Net adverse clinical events (NACEs), defined as a combination of major adverse cardiac events (MACEs) and major bleedings (including therefore all cause death, myocardial infarction and Bleeding Academic Research Consortium (BARC) 3–5 bleeding), were the primary end points, MACEs (a composite of all cause death and myocardial infarction) the secondary one. Single components of NACEs were co-secondary end points, along with BARC 2–5 bleeding, cardiovascular death and stent thrombosis. Results A total of 4424 patients from the RENAMI registry with available data on DAPT duration were included in the model. After propensity score matching, 628 patients from each group were selected. After 20 months of follow up, DAPT for 12 months and DAPT for longer than 12 months significantly reduced the risk of NACE (D1 11.6% vs. D2 6.7% vs. D3 7.2%, p = 0.003) and MACE (10% vs. 6.2% vs. 2.4%, p < 0.001) compared with DAPT for less than 12 months. These differences were driven by a reduced risk of all cause death (7.8% vs. 1.3% vs. 1.6%, p < 0.001), cardiovascular death (5.1% vs. 1.0% vs. 1.2%, p < 0.0001) and recurrent myocardial infarction (8.3% vs. 5.2% vs. 3.5%, p = 0.002). NACEs were lower with longer DAPT despite a higher risk of BARC 2–5 bleedings (4.6% vs. 5.7% vs. 6.2%, p = 0.04) and a trend towards a higher risk of BARC 3–5 bleedings (2.4% vs. 3.3% vs. 3.9%, p = 0.06). These results were not consistent for female patients and those older than 75 years old, due to an increased risk of bleedings which exceeded the reduction in myocardial infarction. Conclusion In unselected real world acute coronary syndrome patients treated with percutaneous coronary intervention, DAPT with prasugrel or ticagrelor prolonged beyond 12 months markedly reduces fatal and non-fatal ischaemic events, offsetting the increased risk deriving from the higher bleeding risk. On the contrary, patients >75 years old and female ones showed a less favourable risk–benefit ratio for longer DAPT due to excess of bleedings.


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