Effect of Classic Secondary Prevention in Type 2 MI: a Target Trial Emulation Study

A classic heart attack is caused by a blockage to the coronary arteries that supplies the heart muscle with oxygenated blood. The medical term for this condition is type 1 myocardial infarction. There is strong scientific evidence that the usage of pharmacological drugs such as statins, beta blockers, Renin-Angiotensin-Aldosterone System blockers and platelet inhibitors after a type 1 myocardial infarction improves survival and reduces the risk for new myocardial infarctions. However, a myocardial infarction may also occur without blockage to the coronary arteries when other acute conditions causes either a decreased supply or an increased demand of oxygenated blood to the heart. The medical term for the latter is type 2 myocardial infarction. There are currently no scientific evidence that any pharmacological drug improves survival in patients with a type 2 myocardial infarction, of whom only one in three patients are alive after five years.

The aim of this study is to investigate if those drugs that improves the prognosis after a type 1 myocardial infarction (Beta blockers, Renin-Angiotensin-Aldosterone System blockers, Statins and platelet inhibitors) also affects the prognosis after a type 2 myocardial infarction.

The best way to answer this question would be to conduct clinical trials for each drug where type 2 myocardial infarction patients are randomized to either receiving the drug of interest or receiving placebo (sugar pills) and then compare the survival and outcomes in both groups over time.

However, clinical trials are costly, time consuming and also difficult to conduct with type 2 myocardial infarction patients since these patients are treated at various hospital departments.

Therefore, this study will instead include patients in a Swedish national register for myocardial infarction, in which myocardial infarction patients are reported from all Swedish hospitals, and compare type 2 myocardial infarction patients that did receive or did not receive each treatment. To minimize the risk of making inaccurate conclusions about the causal relationship between treatment and outcome, the study will define the optimal clinical trial for each treatment and then specifically emulate these trials in all possible aspects using the register data. This method is called "target trial emulation".

Study Overview

• Status: Completed
• Conditions: Myocardial Infarction Type 2
• Intervention / Treatment: Drug: Beta Blocker Therapy or No Therapy (Control); Drug: RAAS blocker Therapy or No therapy (Control); Drug: Statin Therapy or No Therapy (Control); Drug: Dual Antiplatelet Therapy or No Therapy (Control); Drug: Single Antiplatelet Therapy or No Therapy (Control)

Detailed Description

While acute and long term treatments in type 1 myocardial infarction (MI) are well documented, there are no evidence based treatments altering the prognosis in type 2 MI patients, of whom only one in three are alive after five years. Classic secondary preventive treatment in type 1 MI include the use of statins, beta blockers, renin-angiotensin-aldosterone system (RAAS) inhibitors, single antiplatelet therapy (SAPT) and dual antiplatelet therapy (DAPT). While some observational studies suggest classic secondary preventive MI treatment to be associated with better survival in type 2 MI, others do not.

The aim of this study is to investigate if there is an association between treatment with each of statins, beta blockers, RAAS inhibitors, SAPT or DAPT; and all-cause mortality or long-term cardiovascular events in patients with type 2 MI.

The study will be conducted as (several) registry-based observational studies emulating pre-specified target trials. A protocol of a pragmatic randomized controlled trial (a target trial) will be specified for each of statins, beta blockers, RAAS inhibitors, SAPT and DAPT; including eligibility criteria, treatment assignment, time zero and follow up, outcomes, causal contrast and statistical analyses.

Each of these components will then be emulated using registry data. The target trial, as well as the registry-based study emulating the target trial, will differ slightly for each treatment.

The study will include all, approximately 14 000, patients reported as type 2 MI (first reporting for each patient) in the Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies (SWEDEHEART) from 2010 and onward. Data from SWEDEHEART will be merged with data from the National Patient Register, the Swedish Cause of Death Register and the Longitudinal Integrated Database for Health Insurance and Labour Market Studies.

Patients will be followed from hospital discharge (time zero) until death, loss to follow-up or end of follow up (date of data collection). Treatment specific eligibility criteria will be applied at time zero. All important confounding factors at time zero will be identified by drawing causal diagrams, one for each treatment and outcome. Treatment specific models with registry data will then be created to balance the assigned groups using for example inverse probability weighting with multiple imputation of missing data among covariates.

For all target trial emulations, the primary outcome of interest will be a composite endpoint of all-cause mortality, readmission for MI, stroke or heart failure. Secondary outcomes will be all-cause mortality, cardiovascular mortality, readmission for MI, readmission for stroke and readmission for heart failure individually. Safety outcomes will be specified separately for each treatment. Readmission for bacterial pneumonia will be used as a negative control outcome in all target trial emulations to check for residual confounding. Intention-to-treat analysis will be performed for each treatment and outcome. Competing risk methodology will be applied as appropriate.

• Study Type: Observational
• Enrollment (Actual): 14000

Contacts and Locations

Study Locations

• Sweden
  • Uppsala, Sweden, 751 05
    • Department of Medical Sciences, Uppsala University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

All patients reported as type 2 myocardial infarction (first reporting) in the Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies (SWEDEHEART). SWEDEHEART is a Swedish national register for coronary artery disease care and valvular interventions. All Swedish hospitals report to SWEDEHEART. Reported myocardial infarction patients have been classified into type 1-5 since 2010 by the reporting physician. All patients will be included, from the first reporting, until the date of data collection.

Description

Beta blocker target trial emulation:

Inclusion Criteria:

• Reported as Type 2 MI in SWEDEHEART
• Age >18 years
• Alive at time zero (hospital discharge)

Exclusion Criteria:

• Already on beta blocker
• Heart failure with reduced ejection fraction
• Hypertrophic obstructive cardiomyopathy
• Systolic blood pressure <90 mmHg
• Heart rate <50 bpm
• Metastatic cancer (proxy for terminal disease)
• History of dementia or substance abuse last 6 months (proxy for unable to adhere to treatment)
• Missing data for any exclusion criteria

RAAS blocker target trial emulation:

Inclusion Criteria:

• Reported as Type 2 MI in SWEDEHEART
• Age >18 years
• Alive at time zero (hospital discharge)

Exclusion Criteria:

• Already on RAAS blocker
• Heart failure with reduced ejection fraction
• Combination of prior myocardial infarction and diabetes mellitus
• Diabetic nephropathy,
• Systolic blood pressure <90 mmHg
• Hyperkalemia
• Acute renal failure
• Pregnancy
• Metastatic cancer (proxy for terminal disease)
• History of dementia or substance abuse last 6 months (proxy for unable to adhere to treatment)
• Missing data for any exclusion criteria

Statin target trial emulation:

Inclusion Criteria:

• Reported as Type 2 MI in SWEDEHEART
• Age >18 years
• Alive at time zero (hospital discharge)

Exclusion Criteria:

• Already on Statin
• Revascularization during hospitalization
• Obstructive coronary artery disease detected during hospitalization
• History of myocardial infarction or coronary revascularization
• History of stroke
• History of peripheral artery disease
• Familial hypercholesterolemia
• Pregnancy
• Acute or chronic liver failure
• Metastatic cancer (proxy for terminal disease)
• History of dementia or substance abuse last 6 months (proxy for unable to adhere to treatment)
• Missing data for any exclusion criteria

Single Antiplatelet Therapy target trial emulation:

Inclusion Criteria:

• Reported as Type 2 MI in SWEDEHEART
• Age >18 years
• Alive at time zero (hospital discharge)

Exclusion Criteria:

• Already on antiplatelet therapy
• Revascularization during hospitalization
• Obstructive coronary artery disease detected during hospitalization
• Indication for dual antiplatelet therapy according to treating physician
• History of myocardial infarction or coronary revascularization
• History of stroke
• History of peripheral artery disease
• Severe anemia (Hemoglobin <90g/L)
• Intracranial or gastrointestinal bleeding within the last 12 months
• Bleeding disorder
• Acute bleeding during hospitalization
• Metastatic cancer (proxy for terminal disease)
• History of dementia or substance abuse last 6 months (proxy for unable to adhere to treatment)
• Missing data for any exclusion criteria

Dual Antiplatelet Therapy target trial emulation:

Inclusion Criteria:

• Reported as Type 2 MI in SWEDEHEART
• Age >18 years
• Alive at time zero (hospital discharge)

Exclusion Criteria:

• Already on Dual Antiplatelet Therapy
• Revascularization during hospitalization
• Severe anemia (Hemoglobin <90g/L)
• Pregnancy
• Treatment with oral anticoagulants
• Intracranial or gastrointestinal bleeding within the last 12 months
• Bleeding disorder
• Acute bleeding during hospitalization
• Metastatic cancer (proxy for terminal disease)
• History of dementia or substance abuse last 6 months (proxy for unable to adhere to treatment)
• Missing data for any exclusion criteria

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Type 2 myocardial infarction; All patients reported as type 2 myocardial infarction (first reporting) in the Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies (SWEDEHEART)

Drug: Beta Blocker Therapy or No Therapy (Control); Beta blocker therapy or no Beta blocker therapy initiated after type 2 myocardial infarction; Drug: RAAS blocker Therapy or No therapy (Control); RAAS blocker therapy or no RAAS blocker therapy initiated after type 2 myocardial infarction; Drug: Statin Therapy or No Therapy (Control); Statin therapy or no Statin therapy initiated after type 2 myocardial infarction; Drug: Dual Antiplatelet Therapy or No Therapy (Control); Dual Antiplatelet Therapy or no Dual Antiplatelet Therapy initiated after type 2 myocardial infarction; Drug: Single Antiplatelet Therapy or No Therapy (Control); Single Antiplatelet Therapy or no antiplatelet therapy initiated after type 2 myocardial infarction

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Composite	Composite endpoint: All-cause mortality, readmission for MI, stroke or heart failure	From enrollment (hospital discharge after type 2 MI) until Composite endpoint, Loss to follow-up or End of follow up (date of data collection: 05-May-2022)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
All-cause mortality	Death from any cause	From enrollment (hospital discharge after type 2 MI) until Death, Loss to follow-up or End of follow up (date of data collection: 05-May-2022)
Cardiovascular mortality	Death from cardiovascular disease	From enrollment (hospital discharge after type 2 MI) until Cardiovascular death, Loss to follow-up or End of follow up (date of data collection: 05-May-2022). Competing risk methodology applied.
Readmission for MI	Readmission for myocardial infarction	From enrollment (hospital discharge after type 2 MI) until Readmission for MI, Loss to follow-up or End of follow up (date of data collection: 05-May-2022). Competing risk methodology applied.
Readmission for stroke	Readmission for stroke	From enrollment (hospital discharge after type 2 MI) until Readmission for Stroke, Loss to follow-up or End of follow up (date of data collection: 05-May-2022). Competing risk methodology applied.
Readmission for heart failure	Readmission for heart failure	From enrollment (hospital discharge after type 2 MI) until Readmission for Heart failure, Loss to follow-up or End of follow up (date of data collection: 05-May-2022). Competing risk methodology applied.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Readmission for Asthma or COPD	Safety outcome in Beta blocker target trial emulation. Readmission for Asthma or Chronic Obstructive Pulmonary Disease. Only if main diagnosis.	From enrollment (hospital discharge after type 2 MI) until Readmission for Asthma/COPD, Loss to follow-up or End of follow up (date of data collection: 05-May-2022). Competing risk methodology applied.
Readmission for Acute renal failure	Safety outcome in RAAS blocker target trial emulation. Readmission for Acute renal failure.	From enrollment (hospital discharge after type 2 MI) until Readmission for Acute renal failure, Loss to follow-up or End of follow up (date of data collection: 05-May-2022). Competing risk methodology applied.
Readmission for bleeding	Safety outcome in SAPT and DAPT target trial emulations. Readmission for bleeding.	From enrollment (hospital discharge after type 2 MI) until Readmission for Bleeding, Loss to follow-up or End of follow up (date of data collection: 05-May-2022). Competing risk methodology applied.
Readmission for Pneumonia	Negative control outcome in all target trial emulations. Readmission for bacterial pneumonia.	From enrollment (hospital discharge after type 2 MI) until Readmission for bacterial pneumonia, Loss to follow-up or End of follow up (date of data collection: 05-May-2022). Competing risk methodology applied.
Readmission for hip fracture	Additional negative control outcome in all target trial emulations. Readmission for hip fracture.	From enrollment (hospital discharge after type 2 MI) until Readmission for hip fracture, Loss to follow-up or End of follow up (date of data collection: 05-May-2022). Competing risk methodology applied.

Collaborators and Investigators

• Sponsor: Uppsala University

Study record dates

Study Major Dates

• Study Start (Actual): September 3, 2010
• Primary Completion (Actual): May 5, 2022
• Study Completion (Actual): May 5, 2022

Study Registration Dates

• First Submitted: December 11, 2024
• First Submitted That Met QC Criteria: December 13, 2024
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: March 13, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: Statin; Dual antiplatelet therapy; Type 2 myocardial infarction; Beta blocker; Single antiplatelet therapy; Target trial emulation; RAAS blocker; SWEDEHEART
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Necrosis; Myocardial Ischemia; Ischemia; Myocardial Infarction; Infarction; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Neurotransmitter Agents; Adrenergic Agents; Adrenergic Antagonists; Adrenergic beta-Antagonists
• Other Study ID Numbers: TYPE2_MI_TARGET_TRIALS; KF10-0024 (Other Grant/Funding Number: The Swedish Foundation for Strategic Research)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Due to Swedish laws on personal integrity and health data, as well as the Ethics Committee, we are not allowed to make any data included health variables open to the public even if made anonymous. The data could be shared with other researchers after a request to the head of our department

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: Yes