Table 1.
Description of TASTE Randomized Trial, Target Trial, and Target Trial Emulation Using the SWEDEHEART Registry
| Protocol Component | TASTE (Index Randomized Trial) | Target Trial | Target Trial Emulation Using SWEDEHEART |
|---|---|---|---|
| Eligibility criteria | Age 18 years or older between June 15, 2010, and March 25, 2013 | Same as TASTE apart from: | Same as target trial apart from: |
| Diagnosis of ST-elevation myocardial infarction as defined by chest pain suggestive for myocardial ischemia for at least 30 minutes before hospital admission, time from onset of symptoms of less than 24 hours, and an ECG with new ST-segment elevation in two or more contiguous leads of greater than or equal to 0.2 mV in leads V2-V3 and/or greater than or equal to 0.1 mV in other leads or a probable new-onset left bundle branch block. | Study period September 4, 2007, to January 4, 2016, excluding June 15, 2010, to March 25, 2013, which was the period of recruitment for TASTE | No informed consent asked, so not able to exclude those who would have not been asked or who would have declined participation if asked | |
| Planned percutaneous coronary intervention in one of the 29 Swedish, 1 Icelandic, or 1 Danish coronary intervention centers | Only in the Swedish coronary intervention centers | ||
| Minimum of 50% stenosis in culprit artery by visual estimate | Possibility to perform thrombus aspiration not assessed | ||
| Correspondence between ECG findings and culprit artery pathoanatomy | Correspondence between ECG findings and culprit artery pathoanatomy not assessed | ||
| Possibility of performing thrombus aspiration | Individuals excluded if died on same day as percutaneous coronary intervention | ||
| No emergency coronary artery bypass grafting | |||
| No previous randomization in the TASTE trial | |||
| Provided informed consent | |||
| Treatment strategies | 1) No thrombus aspiration followed by percutaneous coronary intervention: balloon dilatation, balloon dilatation and stenting, or direct stenting to achieve antegrade flow. Post-dilatation of stents is optional. | Same as TASTE | Same as target trial |
| 2) Thrombus aspiration followed by percutaneous coronary intervention: thrombus aspiration with an Export aspiration catheter (Medtronic Inc., Santa Rosa, California). Continuous manual suction is performed using a proximal-to-distal approach, which is defined as active aspiration during initial passage of the lesion. In lesions that cannot initially be passed with the thrombus aspiration catheter, it is permitted to dilate the lesion with an angioplasty balloon up to a maximal nominal diameter size of 2.0 mm and attempt to advance the thrombus aspiration catheter for a second time. After thrombus aspiration, percutaneous coronary intervention is done as described above. | |||
| Treatment assignment | Individuals randomized to a treatment strategy (by center) | Individuals would be randomized to a treatment strategy and were aware of the assigned strategy. | Individuals assigned to the strategy that their data were compatible with. Assignment was treated as if randomized within levels of the following baseline covariates: age, sex, hospital, diabetes, body mass index, smoking, hyperlipidemia, hypertension, previous infarction, previous percutaneous coronary intervention, previous coronary artery bypass graft, stenosis class, proportion stenosis in culprit artery, angiography finding, heart rate, systolic blood pressure, diastolic blood pressure, thrombolysis, warfarin, aspirin, clopidogrel, prasugrel, heparin, low molecular weight heparin, bivalirudin, and Gp2b3a inhibitors. |
| Outcomes | Death from any cause | Same as TASTE | Same as target trial apart from: |
| Rehospitalization for myocardial infarction | No stent thrombosis due to few events | ||
| Stent thrombosis | Outcomes identified as following: | ||
| Death from any cause from the Swedish Cause of Death Register by 1 year | |||
| Myocardial infarction from the SWEDEHEART Register by 1 year | |||
| Follow-up | Starts at treatment assignment and ends at date of first outcome (separately for analysis of each outcome), migration, or 1 year | Same as TASTE apart from: Unable to identify migration date Started from day after percutaneous coronary intervention Follow-up to 3 years | Same as target trial |
| Causal contrasts | Intention-to-treat effect, per-protocol effect | Intention-to-treat effect, per-protocol effect | Observational analogue of the per-protocol effect |
| Statistical analysis | Kaplan-Meier plots | For intention-to-treat analyses, survival curves estimated using a pooled logistic regression outcome model with an indicator for assigned treatment group, a flexible time-varying intercept, product terms between treatment group and time, and standardization of the period-specific cumulative probabilities. Comparison of risks via differences and ratios then estimated. | Same per protocol analysis as target trial with adjustment for baseline covariates |
| Treatment differences were assessed with the use of the log-rank test and Cox regression. | Per-protocol analyses use the same technique as above, but restricted to individuals who received their assigned treatment, and with the inclusion of baseline covariates in the outcome models. | ||
| Nonparametric bootstrapping with 200 samples used to calculate 95% confidence intervals. |
Abbreviations: ECG, electrocardiogram; Gp2b3a, glycoprotein 2b/3a; SWEDEHEART, Swedish Web-Based System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies; TASTE, Thrombus Aspiration in ST-Elevation Myocardial Infarction in Scandinavia.