Recurrent atherosclerotic cardiovascular disease events preventable with guideline recommended lipid-lowering treatment following myocardial infarction

Background

The 2018 American Heart Association/American College of Cardiology (AHA/ACC) cholesterol guideline provides recommendations for lipid-lowering therapy (LLT) including statins, ezetimibe and proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i) to prevent recurrent atherosclerotic cardiovascular disease (ASCVD) events in adults with established ASCVD. Many adults with ASCVD who are recommended to take statins, ezetimibe and/or PCSK9i do not receive these medications.

Purpose

To estimate the number of recurrent ASCVD events potentially prevented by population-wide use of guideline recommended LLT following a myocardial infarction (MI).

Methods

We simulated the population-wide impact of receipt of 2018 AHA/ACC cholesterol guideline recommended LLT over 3 and 5 years among US adults with government health insurance through Medicare or commercial health insurance following hospital discharge for MI. We used data from patients with an MI hospitalization in 2018–2019 to estimate the percentage receiving guideline recommended LLT defined by having the medications available to take in the 30 days after their discharge date. We used data from patients with an MI hospitalization in 2013–2016 to estimate the 3 and 5-year cumulative incidence of recurrent ASCVD events (i.e., MI, coronary revascularization or ischemic stroke). The reduction in ASCVD events associated with guideline recommended LLT was estimated from a meta-analysis by the Cholesterol-Lowering Treatment Trialists Collaboration. We conducted a sensitivity analysis estimating the number and percentage of ASCVD events prevented if LLT recommendations from the 2019 European Society of Cardiology/European Atherosclerosis Society (ESC/EAS) cholesterol guideline were followed. We repeated all analyses with recurrent coronary heart disease (i.e., MI or coronary revascularization) and ischemic stroke events as separate outcomes.

Results

Among 279,395 adults with an MI hospitalization in 2018–2019 (mean age 75 years, 54% men, mean low-density lipoprotein cholesterol 92 mg/dL), 27% were receiving guideline recommended LLT. With current lipid-lowering medication use, we estimated that 70,698 (95% CI: 70,311–71,077) and 89,255 (95% CI: 88,841–89,730) ASCVD events would occur in 3 and 5 years, respectively, after MI hospital discharge (Table, top panel). If all patients were to receive 2018 AHA/ACC guideline recommended LLT, the number of ASCVD events was estimated to be reduced by 21.6%, representing 15,264 (95% CI: 14,451–16,679) events prevented over 3 years and 19,271 (95% CI: 18,245–21,055) events prevented over 5 years. A higher number of recurrent ASCVD events were estimated to be averted following the LLT recommendations of the 2019 ESC/EAS cholesterol guideline (Table, bottom panel).

Conclusions

Population-wide implementation of guideline recommended LLT in adults with an MI hospitalization could prevent a substantial number of recurrent ASCVD events.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Amgen Inc.

Factors associated with time to initiation of a PCSK9 inhibitor after hospital discharge for acute myocardial infarction

BACKGROUND

Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) lower atherosclerotic cardiovascular disease (ASCVD) event risk.

OBJECTIVE

Analyze patient characteristics associated with time to PCSK9i initiation following an acute myocardial infarction (AMI).

METHODS

We analyzed characteristics of patients ≥21 years of age in the Marketscan or Medicare databases who initiated a PCSK9i 0-89 days, 90-179 days, or 180-365 days after an AMI between July 2015 and December 2018 (n=1,705). We estimated the cumulative incidence of recurrent ASCVD events before PCSK9i initiation.

RESULTS

Overall, 42%, 25%, and 33% of patients who initiated a PCSK9i did so 0-89 days, 90-179 days, and 180-365 days following AMI hospital discharge, respectively. Taking ezetimibe prior to AMI hospitalization and initiating ezetimibe within 30 days after AMI hospital discharge were each associated with a higher likelihood of PCSK9i initiation in the 0-89 days versus 180-365 days post-discharge (adjusted odds ratio [OR] 1.83, 95% confidence interval [95%CI] 1.35-2.49 and 1.76, 95%CI 1.11-2.80, respectively). Statin use before and statin initiation within 30 days after AMI hospitalization were associated with a lower likelihood of PCSK9i initiation 0-89 days versus 180-365 days post-discharge (adjusted OR 0.64, 95%CI 0.49-0.84 and 0.39, 95%CI 0.28-0.54, respectively). Overall, 8.0%, 10.5%, and 12.5% of patients had an ASCVD event at 90, 180, and 365 days following AMI hospital discharge and before initiating a PCSK9i, respectively.

CONCLUSION

Among patients initiating a PCSK9i after AMI, a low proportion did so within 89 days of hospital discharge. Many patients had a recurrent ASCVD event before treatment initiation.

5191Recurrent coronary heart disease in the year following myocardial infarction among US men and women between 2008 and 2015

Background

Although the risk of recurrent events among adults with coronary heart disease (CHD) has declined considerably from the 1970's in the US and many Western countries, studies from the 2000's show that rates remain high. Women have lower rates of incident CHD but little is known about sex differences in recurrent events in adults with CHD.

Purpose

To examine trends in rates of recurrent myocardial infarction (MI), recurrent CHD, and all-cause mortality following a MI hospitalization between 2008 and 2015 among US men and women. Also, we compared sex differences in event rates among individuals with a MI hospitalization versus their counterparts without a history of CHD.

Methods

Data were used from 1,232,024 (53% women) US adults <65 years of age with commercial health insurance in the MarketScan database and US adults ≥66 years of age with government health insurance through Medicare who had a MI hospitalization between January 1, 2008 and December 31, 2015. For each calendar year, age-standardized sex-specific rates of recurrent MI, recurrent CHD (i.e., recurrent MI or coronary revascularization), and all-cause mortality (in Medicare only) were calculated through 365 days following the hospital discharge date for MI. In a secondary analyses, we assessed the rate of recurrent MI, CHD events and all-cause mortality among women versus men with a history of MI (n=324,283) and without a history of CHD (n=1,297,132) in 2014–2015. For these analyses, adjusted hazard ratios (95% confidence intervals) were calculated using follow-up through December 31, 2016.

Results

From 2008 to 2015, age-standardized rates over 365 days of follow-up for recurrent MI declined by 15%, from 94 to 80 per 1000 person-years, in men and by 14%, from 89 to 77 per 1000 person-years, in women. Age-standardized recurrent CHD rates decreased by 16%, from 163 to 138 per 1000 person-years, in men and by 17%, from 142 to 118 per 1000 person-years, in women. In the Medicare population, age-standardized all-cause mortality rates following MI decreased by 6%, from 446 to 421 per 1000 person-years, in men and by 3%, from 412 to 398 per 1000 person-years, in women. In the secondary analyses, the women-to-men hazard ratios for those with a history of MI and those without prior CHD were 0.97 (0.94–0.99) and 0.67 (0.65–0.69), respectively, for MI, 0.89 (0.87–0.91) and 0.52 (0.51–0.54), respectively, for CHD, and 0.84 (0.83–0.85) and 0.74 (0.73–0.75) respectively, for all-cause mortality.

Conclusion

Reductions in rates of recurrent MI, recurrent CHD, and all-cause mortality within 365 days after hospitalization for MI have been similar for US women and men. The lower risk for events comparing women versus men without prior CHD is attenuated after a MI.

Acknowledgement/Funding

The design and conduct of the study was supported through a research grant from Amgen, Inc.

P3422Contrasting the risk for atherosclerotic cardiovascular disease events among individuals with lower extremity peripheral artery disease, coronary heart disease and cerebrovascular disease

Background

Having more vascular conditions, including coronary heart disease (CHD), cerebrovascular disease and lower extremity artery disease (LEAD), may increase the risk for atherosclerosis cardiovascular disease (ASCVD) events. Specific vascular conditions may increase the ASCVD event rate more than others.

Purpose

To compare the risk for future ASCVD events associated with the number and type of vascular conditions among adults with a history of CHD, cerebrovascular disease and/or LEAD.

Methods

We analyzed data from US adults ≥19 years of age with commercial or Medicare health insurance who had a history of CHD, cerebrovascular disease and/or LEAD as of December 31, 2014 (N=901,391). Individuals were followed through December 31, 2016 (median follow-up: 2 years) for ASCVD events, including myocardial infarction, coronary revascularization, stroke, carotid revascularization and lower extremity amputation or revascularization.

Results

Among individuals included in the current analysis (mean age 63 years, 45% female), 70%, 23% and 7% had 1, 2 and 3 vascular conditions, respectively. After adjustment for sociodemographic and cardiovascular risk factors, the hazard ratio for ASCVD among individuals with 2 and 3 versus 1 vascular conditions was 1.88 (1.85, 1.92) and 2.93 (2.86, 3.00), respectively. Among individuals with 1 vascular condition, the rate of ASCVD events per 1,000 person-years was 46.5 (95% CI 44.1, 49.0), 29.6 (95% CI 29.0, 30.1) and 19.9 (95% CI 19.2, 20.8) for those with LEAD, CHD and cerebrovascular disease, respectively. The multivariable-adjusted hazard ratio (95% CI) for ASCVD events comparing individuals with LEAD only and CHD only versus those with cerebrovascular disease only was 1.84 (1.77, 1.92) and 1.12 (1.08, 1.16), respectively. Among individuals with 2 vascular conditions, the ASCVD event rate per 1,000 person-years was higher in those with LEAD and CHD (122.0, 95% CI 112.5, 132.2) and with LEAD and cerebrovascular disease (92.4, 95% CI 79.9, 106.4), versus those with CHD and cerebrovascular disease (59.1, 95% CI 54.8, 63.6). The multivariable-adjusted hazard ratio (95% CI) comparing individuals with LEAD and CHD and those with LEAD and cerebrovascular disease versus those with CHD and cerebrovascular disease was 1.48 (1.44, 1.53) and 1.49 (1.41, 1.58), respectively.

Conclusion

Among adults with vascular disease, having LEAD confers a higher risk for future ASCVD events than CHD or cerebrovascular disease and this group may benefit from more intensive risk reduction treatment.

Acknowledgement/Funding

Amgen Inc.

P652Lower use of statins among patients with peripheral artery disease compared with those with coronary heart disease

Background

Adults with atherosclerotic cardiovascular disease are recommended to take a statin to reduce their risk for future cardiovascular events. Prior studies suggest that statins are being taken by most adults with coronary heart disease (CHD). However, there are few data on the use of statins among adults with peripheral artery disease (PAD).

Purpose

To compare the use of statins among US adults with a history of PAD versus those with a history of CHD.

Methods

We conducted a retrospective cohort study among US adults ≥19 years of age with commercial or government health insurance who had a history of CHD or PAD as of December 31, 2014 (n=1,006,451, mean age 63 years, 47% male). We used pharmacy claims between January 1 and December 31, 2014 to identify use of any statin and of a high-intensity statin (i.e., atorvastatin 40–80 mg, rosuvastatin 20–40 mg, simvastatin 80 mg). Patients with a history of CHD without PAD (CHD only), both CHD and PAD, and PAD without CHD (PAD only) were analysed. Prevalence ratios for use of any statin and a high-intensity statin among those taking a statin were calculated after multivariable adjustment for sociodemographics and cardiovascular risk factors.

Results

Overall, 69.1% of patients included in the current analysis had CHD only, 21.4% had both CHD and PAD, and 9.5% had PAD only. Overall, 66.0%, 68.2% and 47.5% of patients with CHD only, CHD and PAD, and PAD only were taking a statin. After multivariable adjustment and compared to patients with CHD only, the prevalence ratio for statin use was 1.02 (95% CI 1.01, 1.02) for those with both CHD and PAD and 0.82 (95% CI 0.82, 0.83) for those with PAD only. Among patients taking a statin, 29.4% of those with CHD only, 28.6% of those with both CHD and PAD, and 17.3% of those with PAD only were taking a high-intensity dosage. Compared to patients with CHD only, the multivariable adjusted prevalence ratio for taking a high-intensity dosage was 1.05 (95% CI 1.04, 1.06) for those with both CHD and PAD and 0.71 (95% CI 0.70, 0.73) for those with PAD only.

Conclusion

Adults with PAD receive less intensive statin therapy compared with their counterparts who have CHD. Interventions aimed to increase statin use among patients with PAD are warranted.

Acknowledgement/Funding

This study was supported through a research grant from Amgen, Inc. (Thousand Oaks, CA, USA).