Comparison of healthcare costs before and after a STEMI: A French national health data system-based cohort study.

BACKGROUND: Few studies have investigated real-world healthcare costs following a myocardial infarction (MI) and, to our knowledge, none after an ST-elevation MI (STEMI) specifically. Producing such data is important in order to help evaluate the economic burden of STEMI, but also to feed economic evaluation models and eventually show the economic interest of reducing STEMI incidence. The aim of this study was to estimate the healthcare cost in the year preceding and the year following a STEMI in France, in order to estimate the surplus in healthcare resource consumption after a STEMI. METHODS: This study was conducted from the healthcare system perspective. The individual data from the HIBISCUS-STEMI cohort, which included patients with acute STEMI undergoing primary percutaneous coronary intervention, were matched with the French national health data system (Système National des Données de Santé, SNDS) using a probabilistic method. All expenses (in- and out-hospital) presented for reimbursement were taken into account to estimate a mean annual healthcare cost. RESULTS: A total 258 patients from the HIBISCUS-STEMI cohort were included in this economic study. The total mean healthcare cost was estimated at €3516 before the STEMI, and at €9980 after the STEMI. Hospitalizations constituted the largest cost item, 27 % of the total cost before the STEMI and 41.8 % after the STEMI (Δ + 338.8 %). Follow-up and rehabilitative care represented the second largest cost item (25.9 % before and 18 % after the STEMI, Δ + 96.7 %). Treatments represented 19.4 % of the total cost before the STEMI and 17.2 % after (Δ + 150.8 %). CONCLUSIONS: This study shows a significant surplus (threefold) of healthcare resource consumption in the year following a STEMI compared to the year preceding the STEMI.

Kinetic modelling of myocardial necrosis biomarkers offers an easier, reliable and more acceptable assessment of infarct size.

Infarct size is a major prognostic factor in ST-segment elevation myocardial infarction (STEMI). It is often assessed using repeated blood sampling and the estimation of biomarker area under the concentration versus time curve (AUC) in translational research. We aimed at developing limited sampling strategies (LSS) to accurately estimate biomarker AUC using only a limited number of blood samples in STEMI patients. This retrospective study was carried out on pooled data from five clinical trials of STEMI patients (TIMI blood flow 0/1) studies where repeated blood samples were collected within 72 h after admission to assess creatine kinase (CK), cardiac troponin I (cTnI) and muscle-brain CK (CK-MB). Biomarker kinetics was assessed using previously described biomarker kinetic models. A number of LSS models including combinations of 1 to 3 samples were developed to identify sampling times leading to the best estimation of AUC. Patients were randomly assigned to either learning (2/3) or validation (1/3) subsets. Descriptive and predictive performances of LSS models were compared using learning and validation subsets, respectively. An external validation cohort was used to validate the model and its applicability to different cTnI assays, including high-sensitive (hs) cTnI. 132 patients had full CK and cTnI dataset, 49 patients had CK-MB. For each biomarker, 180 LSS models were tested. Best LSS models were obtained for the following sampling times: T4-16 for CK, T8-T20 for cTnI and T8-T16 for CK-MB for 2-sample LSS; and T4-T16-T24 for CK, T4-T12-T20 for cTnI and T8-T16-T20 for CK-MB for 3-sample LSS. External validation was achieved on 103 anterior STEMI patients (TIMI flow 0/1), and the cTnI model applicability to recommended hs cTnI confirmed. Biomarker kinetics can be assessed with a limited number of samples using kinetic modelling. This opens the way for substantial simplification of future cardioprotection studies, more acceptable for the patients.

Myocardial infarction: Economic, health, and social impacts on informal caregivers.

OBJECTIVES: The aim of the study was to measure the economic impact of informal care (IC) on caregivers assisting myocardial infarction (MI) survivors in France. Health and social impacts were also described. METHODS: Data from the prospective 2008 Health and Disabilities Households Survey (Enquête Handicap-Santé), carried out among the French general population, were used to obtain information about patients with MI and their informal caregivers. To estimate the approximate monetary value of IC, three methods were used: the proxy good method, opportunity cost method (OCM), and contingent valuation method (CVM). A multivariate analysis was performed to determine the associations of the IC duration and the existence of professional care with the health indicators stated by caregivers. RESULTS: The analysis included data from 147 caregivers. The mean value of IC ranged from €9,679 per year using the CVM to €11,288 per year using the OCM (p > .05). The mean willingness to pay for an additional hour of IC was €10.9 (SD = 8.3). A total of 46.2 percent of caregivers reported that IC negatively affected theirs physical condition, and 46.3 percent reported that it negatively affected their psychological health. In addition, 40.1 percent declared that caregiving activity made them anxious and 38.8 percent stated they felt alone. Associations were identified between the duration of IC and feeling the need to be replaced, feeling alone and making sacrifices (p < .05). CONCLUSIONS: Informal caregiver burden may be recognized in health technology assessment in order not to underestimate the cost of strategies and to facilitate the comparability of cost-effectiveness outcomes between studies.

Economic valuation of informal care provided to people after a myocardial infarction in France.

BACKGROUND: The aim of this study was to estimate the mean cost per caregiver of informal care during the first year after myocardial infarction event in France. METHODS: We used the Handicap-Santé French survey carried out in 2008 to obtain data about MI survivors and their caregivers. After obtaining the total number of informal care hours provided by caregiver during the first year after MI event, we estimated the value of informal care using the proxy good method and the contingent valuation method. RESULTS: For MI people receiving informal care, an annual mean cost was estimated at €12,404 (SD = 13,012) with the proxy good method and €12,798 (SD = 13,425) with the contingent valuation method per caregiver during the first year after myocardial infarction event. CONCLUSIONS: The present study suggests that informal care should be included more widely in economic evaluations in order not to underestimate the cost of diseases which induce disability.

Revisiting myocardial necrosis biomarkers: assessment of the effect of conditioning therapies on infarct size by kinetic modelling.

Infarct size is a major predictor of subsequent cardiovascular events following ST-segment elevation myocardial infarction (STEMI) and is frequently used in clinical trials focused on cardioprotection. Approximately assessed through serial blood sampling, it can be accurately measured by imaging techniques, e.g. cardiac magnetic resonance imaging, which is the actual gold standard for infarct size determination but with limited availability in daily practice. We developed a mathematical biomarker kinetic model based on pharmacokinetic compartment models to easily and accurately estimate infarct size using individual data from five clinical trials evaluating the impact of conditioning therapies in STEMI between 2005 and 2013. Serial blood sampling was available in all studies with data regarding creatine kinase (CK), CK specific of cardiomyocytes (CK-MB) and cardiac troponin I. Our model allowed an accurate estimation of biomarker release as a surrogate marker of infarct size and a powerful assessment of conditioning treatments. This biomarker kinetic modelling approach identified CK-MB as the most accurate biomarker in determining infarct size and supports the development of limited sampling strategies that estimate total biomarker amount released with a lower number of samples. It will certainly be a useful add-on to future studies in the field of STEMI and cardioprotection.

Left ventricular global function index by magnetic resonance imaging--a novel marker for assessment of cardiac performance for the prediction of cardiovascular events: the multi-ethnic study of atherosclerosis.

Left ventricular (LV) function is generally assessed independent of structural remodeling and vice versa. The purpose of this study was to evaluate a novel LV global function index (LVGFI) that integrates LV structure with global function and to assess its predictive value for cardiovascular (CV) events throughout adult life in a multiethnic population of men and women without history of CV diseases at baseline. A total of 5004 participants in the Multi-Ethnic Study of Atherosclerosis underwent a cardiac magnetic resonance study and were followed up for a median of 7.2 years. The LVGFI by cardiac magnetic resonance was defined by the ratio of stroke volume divided by LV total volume defined as the sum of mean LV cavity and myocardial volumes. Cox proportional hazard models were constructed to predict the end points of heart failure, hard CV events, and a combined end point of all CV events after adjustment for established risk factors, calcium score, and biomarkers. A total of 579 (11.6%) CV events were observed during the follow-up period. In adjusted models, the end points of heart failure, hard CV events, and all events were all significantly associated with LVGFI (heart failure, hazard ratio=0.64, P<0.0001; hard CV events, hazard ratio=0.79, P=0.007; all events, hazard ratio=0.79, P<0.0001). LVGFI had a significant independent predictive value in the multivariable models for all CV event categories. The LVGFI was a powerful predictor of incident HF, hard CV events, and a composite end point, including all events in this multiethnic cohort.

T2-weighted cardiac MR assessment of the myocardial area-at-risk and salvage area in acute reperfused myocardial infarction: comparison of state-of-the-art dark blood and bright blood T2-weighted sequences.

PURPOSE: To compare different state-of-the-art T2-weighted (T2w) imaging sequences combined with late gadolinium enhancement (LGE) for myocardial salvage area (MSA) assessment by cardiac magnetic resonance (CMR). T2w imaging has been used to assess the myocardial area at risk (AAR) in acute myocardial infarction (AMI) patients, but its clinical application is challenging due to technical and physical limitations. MATERIALS AND METHODS: Thirty patients with reperfused AMI underwent complete CMR imaging 2-5 days after hospital admission. Myocardial AAR and MSA were quantified on four different T2w sequences: (a) free-breathing T2-prepared single-shot balanced steady-state free precession (T2p_ssbSSFP); (b) breathhold T2-weighted acquisition for cardiac unified T2 edema (ACUTE); (c) breathhold T2w dark-blood inversion recovery turbo-spin echo (IR-TSE) (short-term inversion recovery: STIR); and (d) free-breathing high-resolution T2 dark-blood navigated BLADE. The diagnostic performance of each technique was also assessed. RESULTS: Quantitative analysis showed significant differences in myocardial AAR extent as quantified by the four T2w sequences (P < 0.05). There were also significant differences in sensitivity, specificity and overall diagnostic performance. CONCLUSION: Detection and quantification of AAR, and thus of MSA, by T2wCMR in reperfused AMI patients varied significantly between different T2w sequences in the same clinical setting.

Assessment of myocardial fibrosis with cardiovascular magnetic resonance.

Diffuse interstitial or replacement myocardial fibrosis is a common feature of a broad variety of cardiomyopathies. Myocardial fibrosis leads to impaired cardiac diastolic and systolic function and is related to adverse cardiovascular events. Cardiovascular magnetic resonance (CMR) may uniquely characterize the extent of replacement fibrosis and may have prognostic value in various cardiomyopathies. Myocardial longitudinal relaxation time mapping is an emerging technique that could improve CMR's diagnostic accuracy, especially for interstitial diffuse myocardial fibrosis. As such, CMR could be integrated in the monitoring and therapeutic management of a large number of patients. This review summarizes the advantages and limitations of CMR for the assessment of myocardial fibrosis.