The MECKI score initiative: Development and state of the art

Heart failure outpatient clinics resources in Italy: a viewpoint of Italian Society of Cardiology organization

The current paper reports the model organization, level of health care, and type of medical and research activities related to the existing heart failure centers of the Italian Society of Cardiology. Of note, we conduced an internal survey among the members of heart failure working group and related hospital and territorial sites about the quality of care and assistance levels according to the local hospital resources and type of diagnostic therapeutic and management resources. Thirty-two hospital ambulatorial structures have been identified, the centers were equally distributed within the national ground, with similar concentration between north and south regions of the Italian country. We distinguished three different levels of organization: (1) basal territorial clinics in which patients with suspected or already diagnosed heart failure (HF) are initially identified and screened; (2) intermediate clinics in which HF patients can be routinary followed by HF specialists supported by a dedicated staff including imaging and arrythmologist experts, and interventional cardiologist; (3) advanced clinics composed by all the technical and staff resources capable of guarantying repetitive invasive assessment, continuous invasive monitoring, dedicated telemedicine structures focused on more advanced HF management integrated by heart transplantation or mechanical assistance programs. Different type of assistance is supported by a relevant number of research activity primarily conducted by the Italian Society of Cardiology or spontaneous studies arranged by HF specialist members. The number of HF centers has increased over the past few decades in proportion to the progressive rise in HF diagnoses and associated hospitalization. The expansion of ambulatory structures has been facilitated by an increasing socioeconomic and research influence. The quality of HF services in Italy could be raised by improving the network and connections between HF specialists, general practitioners (GPs), caregivers, and other specialists frequently working in this field.

Exercise limitations in amyloid cardiomyopathy assessed by cardiopulmonary exercise testing-A multicentre study

AIMS

Amyloid cardiomyopathy is caused by the deposition of light chain (AL) or transthyretin amyloid (ATTR) fibrils, that leads to a restrictive cardiomyopathy, often resulting in heart failure (HF) with preserved or reduced ejection fraction. This study aimed to determine whether cardiac output reduction or ventilation inefficiency plays a predominant role in limiting exercise in patients with amyloid cardiomyopathy.

METHODS

We conducted a multicentre prospective study in patients with AL or ATTR cardiomyopathy who underwent cardiopulmonary exercise testing across four centres. Patients were compared with a propensity-score matched HF cohort based on age, gender, left ventricular ejection fraction (LVEF), and peak oxygen consumption (VO2).

RESULTS

Data from 267 amyloid patients aged 77 (72, 81) years, 86% male, with a median N-terminal pro B-type natriuretic peptide (NT-proBNP) of 2187 (1140, 4383) ng/L, exercise parameters of peak VO2 of 14.1 (11.6;16.9) mL/min/kg, a minute ventilation to carbon dioxide production (VE/VCO2) slope of 37.4 (32.5, 42.6) and a LVEF of 50% (44%, 59%) were analysed. We identified 251 amyloid cardiomyopathy-HF matches. Amyloid patients had a signifnicantly higher VE/VCO2 slope [37.4, inter quartile range (IQR): 32.7, 43.1 vs. 32.1, IQR: 28.7, 37.0, P < 0.0001], NT-proBNP (2249, IQR: 1187, 4420 vs. 718, IQR: 405, 2161 ng/L, P < 0.001), peak heart rate (121 ± 28 vs. 115 ± 27 beats/min, P = 0.007) and peak ventilation (51, IQR: 42, 62 vs. 43, IQR: 33, 53 L/min, P < 0.0001) with earlier anaerobic threshold (VO2 at AT: 8.9, IQR: 6.8, 10.8 vs. 10.8, IQR: 8.9, 12.7 mL/min/kg, P < 0.0001) compared with HF. Between amyloid patients, AL patients (n = 27) were younger (63, IQR: 58, 70 vs. 78, IQR: 72, 81 years, P < 0.0001), had lower VE/VCO2 slope (35.0, IQR: 30.0, 38.7 vs. 38.0, IQR: 32.8, 43.1, P = 0.019), higher end-tidal carbon dioxide partial pressure both at AT (35.1 ± 4.8 vs. 31.4 ± 4.7 mmHg, P < 0.001) and peak exercise (32, IQR: 28, 35 vs. 30, IQR: 26, 33 mmHg, P = 0.039) as compared with ATTR (n = 233).

CONCLUSIONS

A higher VE/VCO2 slope and an earlier AT, determining functional capacity impairment, was assessed in patients with amyloid cardiomyopathy compared with the matched HF cohort. Additionally, patients with ATTR might display more severe exercise limitations as compared with AL.

Machine Learning-Based Risk Factor Analysis and Prediction Model Construction for the Occurrence of Chronic Heart Failure: Health Ecologic Study

BACKGROUND

Chronic heart failure (CHF) is a serious threat to human health, with high morbidity and mortality rates, imposing a heavy burden on the health care system and society. With the abundance of medical data and the rapid development of machine learning (ML) technologies, new opportunities are provided for in-depth investigation of the mechanisms of CHF and the construction of predictive models. The introduction of health ecology research methodology enables a comprehensive dissection of CHF risk factors from a wider range of environmental, social, and individual factors. This not only helps to identify high-risk groups at an early stage but also provides a scientific basis for the development of precise prevention and intervention strategies.

OBJECTIVE

This study aims to use ML to construct a predictive model of the risk of occurrence of CHF and analyze the risk of CHF from a health ecology perspective.

METHODS

This study sourced data from the Jackson Heart Study database. Stringent data preprocessing procedures were implemented, which included meticulous management of missing values and the standardization of data. Principal component analysis and random forest (RF) were used as feature selection techniques. Subsequently, several ML models, namely decision tree, RF, extreme gradient boosting, adaptive boosting (AdaBoost), support vector machine, naive Bayes model, multilayer perceptron, and bootstrap forest, were constructed, and their performance was evaluated. The effectiveness of the models was validated through internal validation using a 10-fold cross-validation approach on the training and validation sets. In addition, the performance metrics of each model, including accuracy, precision, sensitivity, F1-score, and area under the curve (AUC), were compared. After selecting the best model, we used hyperparameter optimization to construct a better model.

RESULTS

RF-selected features (21 in total) had an average root mean square error of 0.30, outperforming principal component analysis. Synthetic Minority Oversampling Technique and Edited Nearest Neighbors showed better accuracy in data balancing. The AdaBoost model was most effective with an AUC of 0.86, accuracy of 75.30%, precision of 0.86, sensitivity of 0.69, and F1-score of 0.76. Validation on the training and validation sets through 10-fold cross-validation gave an AUC of 0.97, an accuracy of 91.27%, a precision of 0.94, a sensitivity of 0.92, and an F1-score of 0.94. After random search processing, the accuracy and AUC of AdaBoost improved. Its accuracy was 77.68% and its AUC was 0.86.

CONCLUSIONS

This study offered insights into CHF risk prediction. Future research should focus on prospective studies, diverse data, advanced techniques, longitudinal studies, and exploring factor interactions for better CHF prevention and management.

Comparison of Cardiopulmonary Exercise Test Variables to Predict Adverse Events in Patients with Heart Failure

PURPOSE

Given the rising burden of heart failure (HF), stratification of patients at increased risk for adverse events is critical. We aimed to compare the predictive value of various maximal and submaximal cardiopulmonary exercise test (CPET) variables for adverse events in patients with HF.

METHODS

A total of 237 patients with HF (66 (58-73) yr, 30% women, 70% HF with reduced ejection fraction) completed a CPET and had 5 yr of follow-up. Baseline characteristics and clinical outcomes (all-cause mortality, major adverse cardiovascular events, and cardiovascular-related hospitalization) were extracted from electronic patient files. Receiver operating characteristics curves for maximal (e.g., peak V̇O 2 ) and submaximal CPET variables (e.g., VE/V̇CO 2 slope, cardiorespiratory optimal point (COP), V̇O 2 at anaerobic threshold) were compared using the Akaike Information Criterion (AIC) method, whereas their calibration was assessed.

RESULTS

One hundred three participants (43%) reached the composite endpoint, and 55 (23%) died. Percent predicted peak V̇O 2 was the best predictor for adverse outcomes (AIC: 302.6) followed by COP (AIC: 304.3) and relative peak V̇O 2 (mL·(kg·min) -1 , AIC: 304.4). Relative peak V̇O 2 (AIC: 217.1) and COP (AIC: 224.4) were also among the three best predictors for mortality, together with absolute peak V̇O 2 (mL·min -1 , AIC: 220.5). A good calibration between observed and predicted event rate was observed for these variables.

CONCLUSIONS

Percent predicated and relative peak V̇O 2 had the best predictive accuracy for adverse events and mortality, but the submaximal COP had a noninferior predictive accuracy for adverse events in patients with HF. These findings highlight the potential of submaximal exercise testing in patients with HF.

A matter of sex-persistent predictive value of MECKI score prognostic power in men and women with heart failure and reduced ejection fraction: a multicenter study

Background

A sex-based evaluation of prognosis in heart failure (HF) is lacking.

Methods and results

We analyzed the Metabolic Exercise test data combined with Cardiac and Kidney Indexes (MECKI) score registry, which includes HF with reduced ejection fraction (HFrEF) patients. A cross-validation procedure was performed to estimate weights separately for men and women of all MECKI score parameters: left ventricular ejection fraction (LVEF), hemoglobin, kidney function assessed by Modification of Diet in Renal Disease, blood sodium level, ventilation vs. carbon dioxide production slope, and peak oxygen consumption (peakVO2). The primary outcomes were the composite of all-cause mortality, urgent heart transplant, and implant of a left ventricle assist device. The difference in predictive ability between the native and sex recalibrated MECKI (S-MECKI) was calculated using a receiver operating characteristic (ROC) curve at 2 years and a calibration plot. We retrospectively analyzed 7,900 HFrEF patients included in the MECKI score registry (mean age 61 ± 13 years, 6,456 men/1,444 women, mean LVEF 33% ± 10%, mean peakVO2 56.2% ± 17.6% of predicted) with a median follow-up of 4.05 years (range 1.72-7.47). Our results revealed an unadjusted risk of events that was doubled in men compared to women (9.7 vs. 4.1) and a significant difference in weight between the sexes of most of the parameters included in the MECKI score. S-MECKI showed improved risk classification and accuracy (area under the ROC curve: 0.7893 vs. 0.7799, p = 0.02) due to prognostication improvement in the high-risk settings in both sexes (MECKI score >10 in men and >5 in women).

Conclusions

S-MECKI, i.e., the recalibrated MECKI according to sex-specific differences, constitutes a further step in the prognostic assessment of patients with severe HFrEF.

International validation of the Metabolic Exercise test data combined with Cardiac and Kidney Indexes (MECKI) score in heart failure

AIMS

Current European heart failure (HF) guidelines suggest the use of risk score: among them, the Metabolic Exercise test data combined with Cardiac and Kidney Indexes (MECKI) score has demonstrated to be one of the most accurate. However, the risk scores are still poorly implemented in clinical practice, also due to the lack of strong evidence regarding their external validation in different populations. Thus, the current study was designed as an external validation test of the MECKI score in an international multicentre setting.

METHODS AND RESULTS

The study cohort consisted of patients diagnosed with HF with reduced ejection fraction (HFrEF) across international centres (not Italian), retrospectively recruited. Collected data included demographics, HF aetiology, laboratory testing, electrocardiogram (ECG), echocardiographic findings, and cardiopulmonary exercise testing (CPET) results as described in the original MECKI score publication. A total of 1042 patients across 8 international centres (7 European and 1 Asian) were included and followed up from 1998 till 2019. Patients were divided according to the calculated MECKI scores into three subgroups: (i) MECKI score <10%, (ii) 10-20%, and (iii) ≥ 20%. Survival analysis comparison among the three MECKI score subgroups showed a worse prognosis in patients with higher MECKI score value: median event-free survival times were 4396 days for MECKI score <10%, 3457 days for 10-20%, and 1022 days for ≥20% (P < 0.0001). Receiver operating characteristic (ROC) curves and area under the ROC curves (AUC) were like those reported in the original internal validation studies.

CONCLUSION

In patients diagnosed with HFrEF, the power of the MECKI score was confirmed in terms of prognosis and risk stratification, supporting its implementation as advised by the HF guidelines.

Three Weeks of Inpatient Cardiac Rehabilitation Improves Metabolic Exercise Data Combined With Cardiac and Kidney Indexes Scores for Heart Failure With Reduced Ejection Fraction

Background: Heart failure with reduced ejection fraction (HFrEF) has a high mortality rate, and cardiac rehabilitation programs (CRP) reduce HFrEF rehospitalization and mortality rates. Some countries attempt 3 weeks of inpatient CRP (3w In-CRP) for cardiac diseases. However, whether 3w In-CRP reduces the prognostic parameter of the Metabolic Exercise data combined with Cardiac and Kidney Indexes (MECKI) score is unknown. Therefore, we investigated whether 3w In-CRP improves MECKI scores in patients with HFrEF. Methods and Results: This study enrolled 53 patients with HFrEF who participated in 30 inpatient CRP sessions, consisting of 30 min of aerobic exercise twice daily, 5 days a week for 3 weeks, between 2019 and 2022. Cardiopulmonary exercise tests and transthoracic echocardiography were performed, and blood samples were collected, before and after 3w In-CRP. MECKI scores and cardiovascular (CV) events (heart failure rehospitalization or death) were evaluated. The MECKI score improved from a median 23.34% (interquartile range [IQR] 10.21-53.14%) before 3w In-CRP to 18.66% (IQR 6.54-39.94%; P<0.01) after 3w In-CRP because of improved left ventricular ejection fraction and percentage peak oxygen uptake. Patients' improved MECKI scores corresponded with reduced CV events. However, patients who experienced CV events did not have improved MECKI scores. Conclusions: In this study, 3w In-CRP improved MECKI scores and reduced CV events for patients with HFrEF. However, patients whose MECKI scores did not improve despite 3w In-CRP require careful heart failure management.

Larissa Heart Failure Risk Score and Mode of Death in Acute Heart Failure: Insights from REALITY-AHF

Patients with heart failure (HF) patients may die either suddenly (sudden cardiac death/SCD) or progressively from pump failure. The heightened risk of SCD in patients with HF may expedite important decisions about medications or devices. We used the Larissa Heart Failure Risk Score (LHFRS), a validated risk model for all-cause mortality and HF rehospitalization, to investigate the mode of death in 1363 patients enrolled in the Registry Focused on Very Early Presentation and Treatment in Emergency Department of Acute Heart Failure (REALITY-AHF). Cumulative incidence curves were generated using a Fine-Gray competing risk regression, with deaths that were not due to the cause of death of interest as a competing risk. Likewise, the Fine-Gray competing risk regression analysis was used to evaluate the association between each variable and the incidence of each cause of death. The AHEAD score, a well-validated HF risk score ranging from 0 to 5 (atrial fibrillation, anemia, age, renal dysfunction, and diabetes mellitus), was used for the risk adjustment. Patients with LHFRS 2-4 exhibited a significantly higher risk of SCD (HR hazard ratio adjusted for AHEAD score 3.15, 95% confidence interval (CI) (1.30-7.65), p = 0.011) and HF death (adjusted HR for AHEAD score 1.48, 95% CI (1.04-2.09), p = 0.03), compared to those with LHFRS 0,1. Regarding cardiovascular death, patients with higher LHFRS had significantly increased risk compared to those with lower LHFRS (HR 1.44 adjusted for AHEAD score, 95% CI (1.09-1.91), p = 0.01). Lastly, patients with higher LHFRS exhibited a similar risk of non-cardiovascular death compared to those with lower LHFRS (HR 1.44 adjusted for AHEAD score, 95% CI (0.95-2.19), p = 0.087). In conclusion, LHFRS was associated independently with the mode of death in a prospective cohort of hospitalized HF patients.

The importance of re-evaluating the risk score in heart failure patients: An analysis from the Metabolic Exercise Cardiac Kidney Indexes (MECKI) score database

BACKGROUND

The role of risk scores in heart failure (HF) management has been highlighted by international guidelines. In contrast with HF, which is intrinsically a dynamic and unstable syndrome, all its prognostic studies have been based on a single evaluation. We investigated whether time-related changes of a well-recognized risk score, the MECKI score, added prognostic value. MECKI score is based on peak VO₂, VE/VCO₂ slope, Na⁺, LVEF, MDRD and Hb.

METHODS

A multi-centre retrospective study was conducted involving 660 patients who performed MECKI re-evaluation at least 6 months apart. Based on the difference between II and I evaluation of MECKI values (MECKI II - MECKI I = ∆ MECKI) the study population was divided in 2 groups: those presenting a score reduction (∆ MECKI <0, i.e. clinical improvement), vs. patients presenting an increase (∆ MECKI >0, clinical deterioration).

RESULTS

The prognostic value of MECKI score is confirmed also when re-assessed during follow-up. The group with improved MECKI (366 patients) showed a better prognosis compared to patients with worsened MECKI (294 patients) (p < 0.0001). At 1st evaluation, the two groups differentiated by LVEF, V_E/VCO₂ slope and blood Na⁺ concentration, while at 2nd evaluation they differentiated in all 6 parameters considered in the score. The patients who improved MECKI score, improved in all components of the score but hemoglobin, while patients who worsened the score, worsened all parameters.

CONCLUSIONS

This study shows that re-assessment of MECKI score identifies HF subjects at higher risk and that score improvement or deterioration regards several MECKI score generating parameters confirming the holistic background of HF.

Performance of current risk stratification models for predicting mortality in patients with heart failure: a systematic review and meta-analysis

AIMS

There are several risk scores designed to predict mortality in patients with heart failure (HF). This study aimed to assess performance of risk scores validated for mortality prediction in patients with acute HF (AHF) and chronic HF.

METHODS AND RESULTS

MEDLINE and Scopus were searched from January 2015 to January 2021 for studies which internally or externally validated risk models for predicting all-cause mortality in patients with AHF and chronic HF. Discrimination data were analysed using C-statistics, and pooled using generic inverse-variance random-effects model. Nineteen studies (n = 494 156 patients; AHF: 24 762; chronic HF mid-term mortality: 62 000; chronic HF long-term mortality: 452 097) and 11 risk scores were included. Overall, discrimination of risk scores was good across the three subgroups: AHF mortality [C-statistic: 0.76 (0.68-0.83)], chronic HF mid-term mortality [1 year; C-statistic: 0.74 (0.68-0.79)], and chronic HF long-term mortality [≥2 years; C-statistic: 0.71 (0.69-0.73)]. MEESSI-AHF [C-statistic: 0.81 (0.80-0.83)] and MARKER-HF [C-statistic: 0.85 (0.80-0.89)] had an excellent discrimination for AHF and chronic HF mid-term mortality, respectively, whereas MECKI had good discrimination [C-statistic: 0.78 (0.73-0.83)] for chronic HF long-term mortality relative to other models. Overall, risk scores predicting short-term mortality in patients with AHF did not have evidence of poor calibration (Hosmer-Lemeshow P > 0.05). However, risk models predicting mid-term and long-term mortality in patients with chronic HF varied in calibration performance.

CONCLUSIONS

The majority of recently validated risk scores showed good discrimination for mortality in patients with HF. MEESSI-AHF demonstrated excellent discrimination in patients with AHF, and MARKER-HF and MECKI displayed an excellent discrimination in patients with chronic HF. However, modest reporting of calibration and lack of head-to-head comparisons in same populations warrant future studies.

Evidence of a double anaerobic threshold in healthy subjects

AIMS

The anaerobic threshold (AT) is an important cardiopulmonary exercise test (CPET) parameter both in healthy and in patients. It is normally determined with three approaches: V-slope method, ventilatory equivalent method, and end-tidal method. The finding of different AT values with these methods is only anecdotic. We defined the presence of a double threshold (DT) when a ΔVO2 > 15 mL/min was observed between the V-slope method (met AT) and the other two methods (vent AT). The aim was to identify whether there is a DT in healthy subjects.

METHODS AND RESULTS

We retrospectively analysed 476 healthy subjects who performed CPET in our laboratory between 2009 and 2018. We identified 51 subjects with a DT (11% of cases). Cardiopulmonary exercise test data at rest and during the exercise were not different in subjects with DT compared to those without. Met AT always preceded vent AT. Compared to subjects without DT, those with DT showed at met AT lower carbon dioxide output (VCO2), end-tidal carbon dioxide tension (PetCO2) and respiratory exchange ratio (RER), and higher ventilatory equivalent for carbon dioxide (VE/VCO2). Compared to met AT, vent AT showed a higher oxygen uptake (VO2), VCO2, ventilation, respiratory rate, RER, work rate, and PetCO2 but a lower VE/VCO2 and end-tidal oxygen tension. Finally, subjects with DT showed a higher VO2 increase during the isocapnic buffering period.

CONCLUSION

Double threshold was present in healthy subjects. The presence of DT does not influence peak exercise performance, but it is associated with a delayed before acidosis-induced hyperventilation.