Dataset from the article Garatti A, Castelvecchio S, Daprati A, Molfetta R, Volpe M, De Vincentiis C, Parolari A, Menicanti L. Clinical Course of COVID-19 Infection in Patients Urgently Operated of Cardiac Surgical Procedures. Ann Surg. 2020 Oct;272(4):e275-e279. doi: 10.1097/SLA.0000000000004393. PMID: 32932327. Abstract Objective: The aim of this study was to describe the clinical course of a consecutive series of patients operated of urgent cardiac surgery during COVID-19 outbreak. Background: In Italy, COVID outbreak has mostly occurred in the metropolitan area of Milan, and in the surrounding region of Lombardy, and previously "conventional" hospitals were converted into COVID spokes to increase ICU beds availability, and to allow only urgent CS procedures. Methods: Among urgent CS patients (left main stenosis with unstable angina, acute endocarditis, valvular regurgitation with impending heart failure), 10 patients (mean age = 57 ± 9 years), despite a negative admission triage, developed COVID-pneumonia postoperatively, at a median of 7 days after CS. Results: Patients showed typical lymphopenia, higher prothrombotic profile, and higher markers of inflammation (ferritin and interleukin-6 values). At the zenith of pulmonary distress, patients presented with severe hypoxia (median PaO2/FIO2 ratio = 116), requiring advanced noninvasive ventilation (Venturi mask and continuous positive airway pressure) in the majority of cases. All patients were treated with hydroxychloroquine, azithromycin, and low-molecular-weight heparin at anticoagulant dose. Overall in-hospital mortality was 10% (1/10), peaking 25% in patients who developed COVID pneumonia immediately after CS. The remaining patients, with late infection, were all discharged home without oxygen support, at a median of 25 days after symptom onset. Conclusions: As postoperative mortality in case of COVID pneumonia is not negligible, meticulous rules (precise triage, safe hospital path, high level of protection for health-care teams, prompt diagnosis of suspicious symptoms) should be strictly followed in patients undergoing CS during COVID pandemic. The role of therapies alternative to CS should be further assessed.
This study tested the hypothesis that respiration (RESP) is a confounder or suppressor of the closed loop relationship responsible for the cerebrovascular dynamical interactions as assessed from spontaneous variability of mean arterial pressure (MAP) and mean cerebral blood flow (MCBF). The evaluation was carried out in the information domain via transfer entropy (TE) estimated through a linear model-based approach comparing TE markers computed solely over MAP and MCBF series with TE indexes accounting for the eventual action of RESP over MAP and MCBF. We considered 11 patients (age: 76±5 yrs, 7 males) undergoing surgical aortic valve replacement (SAVR) at supine resting (REST) and during active standing (STAND) before and after SAVR surgery. The decrease of the predictive ability of MCBF to MAP when accounting for RESP compared to the one assessed when disregarding RESP suggested that RESP is a confounder of the link from MCBF to MAP along the Cushing reflex instead of being a suppressor. This result was more evident in POST when autonomic control was dramatically depressed and in an unchallenged condition such as REST. RESP did not affect significantly the link from MAP to MCBF along the pressure-to-flow relationship. Clarification of the type of RESP influence on the MAP-MCBF closed loop relationship could favor a deeper characterization of cerebrovascular interactions and the comprehension of cerebral autoregulation mechanisms.Clinical Relevance— This study suggests that respiration is a confounder of the closed loop relationship between MAP and MCBF, especially of the flow-to-pressure causal link. This result might open new possibilities in elucidating the mechanisms of cerebral autoregulation in healthy and pathological populations.
Porta A, Gelpi F, Bari V, Cairo B, De Maria B, Panzetti CM, Cornara N, Bertoldo EG, Fiolo V, Callus E, De Vincentiis C, Volpe M, Molfetta R, Pistuddi V, Ranucci M. Monitoring the Evolution of Asynchrony between Mean Arterial Pressure and Mean Cerebral Blood Flow via Cross-Entropy Methods. Entropy (Basel). 2022 Jan 2;24(1):80. doi: 10.3390/e24010080. PMID: 35052106; PMCID: PMC8774596. Abstract Cerebrovascular control is carried out by multiple nonlinear mechanisms imposing a certain degree of coupling between mean arterial pressure (MAP) and mean cerebral blood flow (MCBF). We explored the ability of two nonlinear tools in the information domain, namely cross-approximate entropy (CApEn) and cross-sample entropy (CSampEn), to assess the degree of asynchrony between the spontaneous fluctuations of MAP and MCBF. CApEn and CSampEn were computed as a function of the translation time. The analysis was carried out in 23 subjects undergoing recordings at rest in supine position (REST) and during active standing (STAND), before and after surgical aortic valve replacement (SAVR). We found that at REST the degree of asynchrony raised, and the rate of increase in asynchrony with the translation time decreased after SAVR. These results are likely the consequence of the limited variability of MAP observed after surgery at REST, more than the consequence of a modified cerebrovascular control, given that the observed differences disappeared during STAND. CApEn and CSampEn can be utilized fruitfully in the context of the evaluation of cerebrovascular control via the noninvasive acquisition of the spontaneous MAP and MCBF variability.
Dataset from the article Porta A, Fantinato A, Bari V, Gelpi F, Cairo B, De Maria B, Bertoldo EG, Fiolo V, Callus E, De Vincentiis C, Volpe M, Molfetta R, Ranucci M. Evaluation of the impact of surgical aortic valve replacement on short-term cardiovascular and cerebrovascular controls through spontaneous variability analysis. PLoS One. 2020 Dec 10;15(12):e0243869. doi: 10.1371/journal.pone.0243869. PMID: 33301491; PMCID: PMC7728248. Abstract We assessed the effect of surgical aortic valve replacement (SAVR) on cardiovascular and cerebrovascular controls via spontaneous variability analyses of heart period, approximated as the temporal distance between two consecutive R-wave peaks on the electrocardiogram (RR), systolic, diastolic and mean arterial pressure (SAP, DAP and MAP) and mean cerebral blood flow (MCBF). Powers in specific frequency bands, complexity, presence of nonlinear dynamics and markers of cardiac baroreflex and cerebral autoregulation were calculated. Variability series were acquired before (PRE) and after (POST) SAVR in 11 patients (age: 76±5 yrs, 7 males) at supine resting and during active standing. Parametric spectral analysis was performed based on the autoregressive model. Complexity was assessed via a local nonlinear prediction approach exploiting the k-nearest-neighbor strategy. The presence of nonlinear dynamics was checked by comparing the complexity marker computed over the original series with the distribution of the same index assessed over a set of surrogates preserving distribution and power spectral density of the original series. Cardiac baroreflex and cerebral autoregulation were estimated by assessing the transfer function from SAP to RR and from MAP to MCBF and squared coherence function via the bivariate autoregressive approach. We found that: i) orthostatic challenge had no effect on cardiovascular and cerebrovascular control markers in PRE; ii) RR variance was significantly reduced in POST; iii) complexity of SAP, DAP and MAP variabilities increased in POST with a greater likelihood of observing nonlinear dynamics over SAP compared to PRE at supine resting; iv) the amplitude of MCBF variations and MCBF complexity in POST remained similar to PRE; v) cardiac baroreflex sensitivity decreased in POST, while cerebrovascular autoregulation was preserved. SAVR induces important changes of cardiac and vascular autonomic controls and baroreflex regulation in patients exhibiting poor reactivity of cardiovascular regulatory mechanisms, while cerebrovascular autoregulation seems to be less affected.
Porta A, Gelpi F, Bari V, Cairo B, De Maria B, Tonon D, Rossato G, Ranucci M, Faes L. Categorizing the Role of Respiration in Cardiovascular and Cerebrovascular Variability Interactions. IEEE Trans Biomed Eng. 2021 Dec 14;PP. doi: 10.1109/TBME.2021.3135313. Epub ahead of print. PMID: 34905489. Abstract Objective: Respiration disturbs cardiovascular and cerebrovascular controls but its role is not fully elucidated. Methods: Respiration can be classified as a confounder if its observation reduces the strength of the causal relationship from source to target. Respiration is a suppressor if the opposite situation holds. We prove that a confounding/suppression (C/S) test can be accomplished by evaluating the sign of net redundancy/synergy balance in the predictability framework based on multivariate autoregressive modelling. In addition, we suggest that, under the hypothesis of Gaussian processes, the C/S test can be given in the transfer entropy decomposition framework as well. Experimental protocols: We applied the C/S test to variability series of respiratory movements, heart period, systolic arterial pressure, mean arterial pressure, and mean cerebral blood flow recorded in 17 pathological individuals (age: 648 yrs; 17 males) before and after induction of propofol-based general anesthesia prior to coronary artery bypass grafting, and in 13 healthy subjects (age: 278 yrs; 5 males) at rest in supine position and during head-up tilt with a table inclination of 60. Results: Respiration behaved systematically as a confounder for cardiovascular and cerebrovascular controls. In addition, its role was affected by propofol-based general anesthesia but not by a postural stimulus of limited intensity. Conclusion: The C/S test can be fruitfully exploited to categorize the role of respiration over causal variability interactions.
Dataset from the article Toso A, Castelvecchio S, Menicanti L, Volpe M, Fantini F. Prognostic value of natriuretic peptides and restrictive filling pattern before surgical ventricular restoration. J Thorac Cardiovasc Surg. 2020 Oct 15:S0022-5223(20)32827-0. doi: 10.1016/j.jtcvs.2020.09.132. Epub ahead of print. PMID: 33168168. AbstractObjective: Both increased natriuretic peptide levels and restrictive filling pattern (RFP) are important risk predictors in patients with heart failure. The aim of this study was to examine the role of the combined use of natriuretic peptide and RFP for the prognostic stratification of patients with ischemic cardiomyopathy undergoing surgical ventricular restoration in the Biomarker Plus study. Methods: A total of 186 patients (aged 64 ± 10 years) underwent echocardiographic study and N-terminal pro-B-type natriuretic peptide assay at baseline (before surgical ventricular restoration). Patients were divided into 4 groups depending on baseline diastolic filling pattern (RFP/no RFP) and N-terminal pro-B-type natriuretic peptide level (less than or greater than or equal to the upper tertile value of 2003 ŋg/L). RFP was defined as E/A ratio ≥2. All-cause death or heart failure hospitalizations within 36-month follow-up were analyzed. Results: Despite similar ejection fraction, volumes, and mass, the 4 groups presented distinct clinical and structural pattern of presurgical ventricular restoration ventricular remodeling and significantly different clinical outcome after surgical unloading. During follow-up, 67 patients died or were hospitalized for heart failure (36%). High N-terminal pro-B-type natriuretic peptide levels and RFP, considered individually, were significantly associated with outcome (P < .0001). The combination of both was associated with the highest adjusted hazard of adverse events (hazard ratio, 3.63; 95% CI, 1.73-7.6; P < .0001). Conclusions: The simultaneous use of 2 markers, 1 biological and 1 echocardiographic, may allow better prognostic stratification and characterization of the distinct structural and clinical phenotypes in a population of patients with ischemic cardiomyopathy undergoing surgical ventricular restoration. This approach could be useful in the decision-making process to guide treatment choices in patients with ischemic cardiomyopathy.
Introduction: there is considerable evidence that psychosocial factors contribute in the etiology and the prognosis of cardiac illness. Currently, in Italy, psychologists are only obligatory in the cardiac rehabilitation setting, although there are indications that the patients could be experiencing distress also during other moments of hospitalization, when admitted for cardiac surgery. Objective and methods: the objective of this protocol is to gain more information about the cardiac patients, specifically during the various moments of hospitalization for cardiac surgery, by collecting data at admittance before cardiac surgery (t0), at admittance in cardiac rehabilitation (t1) and at discharge (t2) at the IRCCS Policlinico San Donato Hospital. A psychosocial questionnaire was constructed after consulting the relevant national and international guidelines. Patients admitted for cardiac surgery and attending a rehabilitation program, will be evaluated by acquiring data about their civil status, religiosity, education and work capacity, social condition (including the presence and quality of intimate relationships and support received), previous psychological and psychiatric history, psychological status, lifestyle (including questions on nutrition, smoking, alcohol and substance abuse, with the administration of the Fagerström test for smokers), adherence to therapy (Morinsky test) quality of life (Satisfaction with Life Scale and a numerical rating scale ranging from 0-100), health perception (EuroQoL,only the numerical rating scale 0-100) and anxiety and depression (Hospital Anxiety and Depression Scale) at t0. Health perception, anxiety and depression are also measured at t1 and t2. Discussion and conclusions: This study is an attempt to identify the recommended psychosocial variables whichwhich need to be monitored during the cardiac patients' hospitalization for cardiac surgery, until cardiac rehabilitation. After implementing this study at the IRCCS Policlinico San Donato, attempts will be made to create studies on a national and international level to generate more evidence regarding these variables, in order to create tailor made interventions for these patients during these specific and delicate moments.
Porta A, Gelpi F, Bari V, Cairo B, De Maria B, Tonon D, Rossato G, Ranucci M, Faes L. Categorizing the Role of Respiration in Cardiovascular and Cerebrovascular Variability Interactions. IEEE Trans Biomed Eng. 2021 Dec 14;PP. doi: 10.1109/TBME.2021.3135313. Epub ahead of print. PMID: 34905489. Abstract Objective: Respiration disturbs cardiovascular and cerebrovascular controls but its role is not fully elucidated. Methods: Respiration can be classified as a confounder if its observation reduces the strength of the causal relationship from source to target. Respiration is a suppressor if the opposite situation holds. We prove that a confounding/suppression (C/S) test can be accomplished by evaluating the sign of net redundancy/synergy balance in the predictability framework based on multivariate autoregressive modelling. In addition, we suggest that, under the hypothesis of Gaussian processes, the C/S test can be given in the transfer entropy decomposition framework as well. Experimental protocols: We applied the C/S test to variability series of respiratory movements, heart period, systolic arterial pressure, mean arterial pressure, and mean cerebral blood flow recorded in 17 pathological individuals (age: 648 yrs; 17 males) before and after induction of propofol-based general anesthesia prior to coronary artery bypass grafting, and in 13 healthy subjects (age: 278 yrs; 5 males) at rest in supine position and during head-up tilt with a table inclination of 60. Results: Respiration behaved systematically as a confounder for cardiovascular and cerebrovascular controls. In addition, its role was affected by propofol-based general anesthesia but not by a postural stimulus of limited intensity. Conclusion: The C/S test can be fruitfully exploited to categorize the role of respiration over causal variability interactions.