Cost of cardiovascular disease prevention: towards economic evaluations in prevention programs

Optimizing cardiovascular disease mortality prediction: a super learner approach in the tehran lipid and glucose study

BACKGROUND & AIM

Cardiovascular disease (CVD) is the most important cause of death in the world and has a potential impact on health care costs, this study aimed to evaluate the performance of machine learning survival models and determine the optimum model for predicting CVD-related mortality.

METHOD

In this study, the research population was all participants in Tehran Lipid and Glucose Study (TLGS) aged over 30 years. We used the Gradient Boosting model (GBM), Support Vector Machine (SVM), Super Learner (SL), and Cox proportional hazard (Cox-PH) models to predict the CVD-related mortality using 26 features. The dataset was randomly divided into training (80%) and testing (20%). To evaluate the performance of the methods, we used the Brier Score (BS), Prediction Error (PE), Concordance Index (C-index), and time-dependent Area Under the Curve (TD-AUC) criteria. Four different clinical models were also performed to improve the performance of the methods.

RESULTS

Out of 9258 participants with a mean age of (SD; range) 43.74 (15.51; 20-91), 56.60% were female. The CVD death proportion was 2.5% (228 participants). The death proportion was significantly higher in men (67.98% M, 32.02% F). Based on predefined selection criteria, the SL method has the best performance in predicting CVD-related mortality (TD-AUC > 93.50%). Among the machine learning (ML) methods, The SVM has the worst performance (TD-AUC = 90.13%). According to the relative effect, age, fasting blood sugar, systolic blood pressure, smoking, taking aspirin, diastolic blood pressure, Type 2 diabetes mellitus, hip circumference, body mss index (BMI), and triglyceride were identified as the most influential variables in predicting CVD-related mortality.

CONCLUSION

According to the results of our study, compared to the Cox-PH model, Machine Learning models showed promising and sometimes better performance in predicting CVD-related mortality. This finding is based on the analysis of a large and diverse urban population from Tehran, Iran.

Postprandial Plasma Glucose Measured from Blood Taken between 4 and 7.9 h Is Positively Associated with Mortality from Hypertension and Cardiovascular Disease

It is unknown whether postprandial plasma glucose measured from blood taken between 4 and 7.9 h (PPG4-7.9h) is associated with mortality from hypertension, diabetes, or cardiovascular disease (CVD). This study aimed to investigate these associations in 4896 US adults who attended the third National Health and Nutrition Examination Survey. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of PPG4-7.9h for mortality. This cohort was followed up for 106,300 person-years (mean follow-up, 21.7 years). A 1-natural-log-unit increase in PPG4-7.9h was associated with a higher risk of mortality from hypertension (HR, 3.50; 95% CI, 2.34-5.24), diabetes (HR, 11.7; 95% CI, 6.85-20.0), and CVD (HR, 2.76; 95% CI, 2.08-3.68) after adjustment for all the tested confounders except hemoglobin A1c (HbA1c). After further adjustment for HbA1c, PPG4-7.9h remained positively associated with mortality from both hypertension (HR, 2.15; 95% CI, 1.13-4.08) and CVD (HR, 1.62; 95% CI, 1.05-2.51), but was no longer associated with diabetes mortality. Subgroup analyses showed that similar results were obtained in the sub-cohort of participants without a prior diagnosis of myocardial infarction or stroke. In conclusion, PPG4-7.9h predicts mortality from hypertension and CVD, independent of HbA1c.

Optimizing Cardiac Wireless Implant Communication: A Feasibility Study on Selecting the Frequency and Matching Medium

Cardiac wireless implantable medical devices (CWIMD) have brought a paradigm shift in monitoring and treating various cardiac conditions, including heart failure, arrhythmias, and hypertension. One of the key elements in CWIMD is the implant antenna which uses radio frequency (RF) technology to wirelessly communicate and transmit data to external devices. However, wireless communication with a deeply implanted antenna using RF can be challenging due to the significant loss of electromagnetic (EM) signal at the air-skin interface, and second, due to the propagation and reflection of EM waves from different tissue boundaries. The air-skin interface loss of the EM wave is pronounced due to the absence of a matching medium. This paper investigates the EM propagation losses in the human body and presents a choice of optimal frequency for the design of the cardiac implant antenna and the dielectric properties of the matching medium. First, the dielectric properties of all tissues present in the human thorax including skin, fat, muscle, cartilage, and heart are analyzed as a function of frequency to study the EM wave absorption at different frequencies. Second, the penetration of EM waves inside the biological tissues is analyzed as a function of frequency. Third, a transmission line (TL) formalism approach is adopted to examine the optimal frequency band for designing a cardiac implant antenna and the matching medium for the air-skin interface. Finally, experimental validation is performed at two ISM frequencies, 433 MHz and 915 MHz, selected from the optimal frequency band (0.4-1.5 GHz) suggested by our analytical investigation. For experimental validation, two off-the-shelf flexible dipole antennas operating at selected ISM frequencies were used. The numerical and experimental findings suggested that for the specific application of a cardiac implant with a penetration depth of 7-17 cm, the most effective frequency range for operation is within 0.4-1.5 GHz. The findings based on the dielectric properties of thorax tissues, the penetration depth of EM waves, and the optimal frequency band have provided valuable information on developing and optimizing CWIMDs for cardiac care applications.

Why and How Should We Assess the Cardiovascular Risk in Patients with Juvenile Idiopathic Arthritis? A Single-Centre Experience with Carotid Intima-Media Measurements

Background: Children diagnosed with juvenile idiopathic arthritis (JIA) are thought to be more likely to develop cardiovascular disease in adulthood. The factors modulating the cardiovascular risk, involving exposure to secondhand smoking, sedentary lifestyle and abnormal body mass index, might have had a stronger impact during the COVID-19 pandemic. The lack of reliable prognostic markers for a higher probability of cardiovascular events might be solved by carotid intima-media thickness (cIMT) measurement. The paramount goal of the study was to assess its usefulness in JIA patients. Materials and Methods: The results of cIMT measured by a single physician in 45 children diagnosed with JIA were compared to 37 age- and sex-matched healthy counterparts. The analysis also involved anthropometric parameters, laboratory tests, and a survey regarding lifestyle-related factors. Results: Four JIA patients appeared to have cIMT above the 94th percentile. A positive correlation between erythrocytes sedimentation rate (ESR) and right carotid artery percentiles was found. Passive smoking increased the cardiovascular risk regardless of JIA. Doubling the daily screen time during the pandemic led to a significant reduction in children’s physical activity. However, the number of enrolled subjects was not enough to make significant recommendations. Conclusions: cIMT measurements remain an interesting perspective for future cardiovascular screening of children with JIA. It has yet to be determined whether it should be considered in all JIA patients on a reliable basis.

Cost-Effectiveness of the CNIC-Polypill Strategy Compared With Separate Monocomponents in Secondary Prevention of Cardiovascular and Cerebrovascular Disease in Portugal: The MERCURY Study

Background: Cardiovascular (CV) diseases remain a leading and costly cause of death globally. Patients with previous CV events are at high risk of recurrence. Secondary prevention therapies improve CV risk factor control and reduce disease costs. Objectives: To assess the cost-effectiveness of a CV polypill strategy (CNIC-Polypill) compared with the loose combination of monocomponents to improve the control of CV risk factors in patients with previous coronary heart disease or stroke. Methods: A Markov model cost-utility analysis was developed using 4 health states, SMART risk equation, and 3-month cycles for year 1 and annual cycles thereafter, over a lifetime horizon from the perspective of the National Health System in Portugal (base case). The NEPTUNO study, Portuguese registries, mortality tables, official reports, and the literature were consulted to define effectiveness, epidemiological costs, and utility data. Outcomes were costs (estimated in 2020 euros) per life-year (LY) and quality-adjusted LY (QALY) gained. A 4% discount rate was applied. Alternative scenarios and one-way and probabilistic sensitivity analyses tested the consistency and robustness of results. Results: The CNIC-Polypill strategy in secondary prevention provides more LY and QALY, at a higher cost, than monocomponents. The incremental cost-utility ratio is €1557/QALY gained. Assuming a willingness-to-pay threshold of €30 000/QALY gained, there is a 79.7% and a 44.4% probability of the CNIC-Polypill being cost-effective and cost-saving, respectively, compared with the loose combination of monocomponents. Results remain consistent in the alternative scenarios and robust in the sensitivity analyses. Discussion: The model reflects increments in the number of years patients would live and in quality of life with the CNIC-Polypill. The clinical effectiveness of the CNIC-Polypill strategy initially demonstrated in the NEPTUNO study has been recently corroborated in the SECURE trial. The incremental cost of the CNIC-Polypill strategy emerges slightly above the comparator, but willingness-to-pay estimates and sensitivity analyses indicate that the CNIC-Polypill strategy is consistently cost-effective compared with monocomponents and remains within acceptable affordability margins. Conclusion: The CNIC-Polypill is a cost-effective secondary prevention strategy. In patients with histories of coronary heart disease or stroke, the CNIC-Polypill more effectively controls CV risk factors compared with monocomponents.

Reduction in medical costs for cardiovascular diseases through innovative health awareness projects in a rural area in Japan

To promote health awareness and improve life expectancy in Hirosaki, a Japanese rural area, the Center of Healthy Aging Program (CHAP) was founded in 2013. The most important characteristic of CHAP is a personalized interview just after the checkup to discuss individual results. We evaluated the clinical and economic effects of CHAP by analyzing the cohort data of voluntary participants from annual health checkups since 2005 in the Iwaki district of Hirosaki. We calculated 10-year incidence risk scores for coronary heart diseases (CHDs) and stroke, and compared the risk-score trend before and after the start of CHAP by adjusting other risk factors using multivariate generalized linear regression analyses. We also predicted the 10-year incidences of CHDs and stroke based on the risk scores, for future scenarios of the two conditions, with and without CHAP, and compared them to their treatment costs between scenarios. The number of participants ranged between 808 and 1,167, from 2008 to 2016. The mean age (55 years) and proportion of women (60%) did not significantly change throughout the period. After adjusting for sex, age, outside temperature on the checkup date, the preparation effect of CHAP in 2012, and risk scores in the previous year, the annual increases in risk scores of CHDs and stroke were significant even after CHAP (+0.413, p <0.001; +0.169, p <0.001, respectively), but slightly less compared to before CHAP (+2.638, p <0.001; +1.155, p <0.001, respectively). Assuming the trend continued until 2021, the 10-year incidences of CHDs and stroke have decreases by 22,486 and 9,603, respectively, and treatment costs decreased by JPY 21,973 and 16,056 million, respectively. CHAP contributes to a significant decrease in the incidences of CHDs and stroke, and reduces economic burden on the local government.

Hospitalization Expenses and Influencing Factors for Inpatients with Ischemic Heart Disease in Iran: A Retrospective Study

Background: Ischemic heart disease (IHD) is the leading cause of death and disability worldwide and in Iran, which imposes a heavy financial burden both on patient’s family and society. Objectives: This study aimed to analyze the direct medical costs of inpatients with IHD and its influencing factors in Iran in 2020. Methods: The sample of this cross-sectional study included 41,357 patients with IHD selected from the hospital information system (HIS) of the Iran Health Insurance Organization from August 23, 2019, to June 20, 2020. The study used the claims data of these patients, which included their demographics, length of stay (LOS), intensive care unit (ICU) admission, hospital accreditation grade, hospital ownership type, and patient discharge status. The multiple linear regression model was employed to evaluate the relationship between hospitalization costs and the associated factors. All statistical tests were conducted at the significance level of P < 0.05 using the R 3.6.3 software. Results: The mean age of patients was 63.95 ± 12.63 years old, and most of them were male (54.4%). The mean hospitalization cost per patient and per day was 586.42 ± 472.51 USD and 103.64 ± 100.29 USD, respectively. Moreover, the mean LOS was 4.92 days. Drugs and consumable medical supplies, as well as nursing and hoteling services, had the highest shares of hospitalization costs (29.54% and 29.4%, respectively). The hospitalization costs of patients with IHD were higher among men (β = 1.24), age 61 - 70 years (β = 1.38), LOS ≥ 5 (β = 2.92), ICU admission (β = 1.62), Iranian health fund (β = 1.21), and private hospitals (β = 1.91). Top-grade and first-grade hospitals had higher costs compared to grade 2 (β = 0.67), grade 3 (β = 0.35), and grade 4 (β = 0.72) hospitals. Deceased patients had also higher costs than patients with complete recovery (β = 0.63), relative recovery (β = 0.59), follow-up (β = 0.51), transfer to other medical centers (β = 0.44), and discharge against medical advice (DAMA) (β = 0.62). Conclusions: According to the results, shortening the LOS and controlling the high costs of drugs and consumable medical supplies are among the main strategies to reduce high hospitalization costs.

Cerebrovascular development: mechanisms and experimental approaches

The cerebral vasculature plays a central role in human health and disease and possesses several unique anatomic, functional and molecular characteristics. Despite their importance, the mechanisms that determine cerebrovascular development are less well studied than other vascular territories. This is in part due to limitations of existing models and techniques for visualisation and manipulation of the cerebral vasculature. In this review we summarise the experimental approaches used to study the cerebral vessels and the mechanisms that contribute to their development.

INFLUENCE OF ACUTE CORONARY SYNDROME ON INTRAOPERATIVE DYNAMICS OF IL-6 DURING CORONARY REVASCULARIZATION

Percutaneous x-ray endovascular angioplasty is one of the most modern methods of treatment of severe forms of cardiovascular diseases. In the pathogenesis of acute coronary syndrome, a special place is occupied by the proinflammatory reaction of the body. The main “secondary” marker is interlekin-6. The peak of its production occurs on the first day of damage and correlates with its size. The aim of the study. To investigate the dynamics of interleukin-6 level in the perioperative period of coronary revascularization, depending on the presence of acute coronary syndrome. Materials and methods. This study included 68 patients with coronary artery disease. The patients were divided into three study groups. Group 1 and 2 patients were diagnosed with ACS, and they underwent emergency stenting of coronary vessels in order to recanalize occlusion of the coronary arteries. 3rd group patients did not have ACS and they were recanalized as planned. Results. Analyzing the results of the study, we found that the highest obtained values of IL-6 were in group 1 in comparison with the group of patients who were surgically treated as planned and after stent placement, the interleukin values were 24.8 % higher in group 1 than in group 2 and almost 4 times higher in group 3 (p<0.001). When comparing groups with acute coronary syndrome, interleukin-6 indices were significantly higher by 47.4 % before surgery in group 3 and by 24.9 % after stent placement, which once again confirms the severity of patients with acute myocardial infarction. Conclusions. Intraoperatively proinflammatory interlekin-6 after coronary artery stenting tends to increase in groups with acute coronary syndrome, while in the group with stable angina, these indicators are significantly higher by 22.8 % (p <0.001). The dynamics of Il-6 levels clearly correlates with the severity of the patient's condition and increases in the presence of acute coronary syndrome, especially in the presence of acute myocardial infarction.