Published online Jun 6, 2019. doi: 10.12998/wjcc.v7.i11.1291
Peer-review started: March 4, 2019
First decision: April 18, 2019
Revised: April 26, 2019
Accepted: May 1, 2019
Article in press: May 2, 2019
Published online: June 6, 2019
Acute myocardial infarction (AMI) continues to cause morbidity and mortality, with the outcomes worsened by the development of cardiogenic shock (CS). Classical management of AMI in the setting of CS is based on hemodynamic monitoring and the use of vasopressor, as well as inotropic agents. To effectively monitor and control hemodynamic changes, techniques such as Pulse index Continuous Cardiac output (PiCCO) can be applied. In PiCCO, a central venous pressure (CVP) catheter and a thermodilution arterial line are used to monitor pressure changes thereby enabling precise evaluation of cardiovascular functions. The technique has been applied in hemodynamic assessments of conditions such as septic shock and acute respiratory syndrome. However, there is scanty utilization of the technique reported in the management of AMI complicated by CS, more so among elderly patients.
During AMI, compromised cardiovascular functions leading to CS often occur, and this can be fatal in the absence of timely intervention. Hemodynamic changes that manifest in the setting of CS can cause heart failure and inadequate tissue perfusion. Accurate and precise measurement of hemodynamic parameters that reflect the changes experienced during CS is critical for adequate management of the condition. There is clinical need to adopt methods and techniques that can provide the clinician with accurate hemodynamic changes for appropriate measures to be instituted to correct the condition. When this is achieved, better prognosis following CS after AMI can be attained.
The main objective of the study was to explore the usefulness of PiCCO in the management of elderly patients who have suffered from AMI and developed CS. Accordingly, the study aimed to evaluate and compare various hemodynamic parameters reflective of vascular tone and myocardial contractility among patients who received the PiCCO services and the control group, which was not assigned to receive PiCCO. A further objective was to compare the clinical outcomes and functional status, as described by daily activity life scores, in addition to the duration of hospitalization between the two groups.
This was a prospective clinical trial study involving patients who satisfied predetermined inclusion criteria, which included being over 65-years-old and having suffered from AMI, together with encountering CS. All participants or their legal representatives provided written informed consent to participate in the study, which received ethical approval from the Review Board of the PLA General Hospital, Beijing, China. Diagnosis of AMI was confirmed using classic clinical techniques such as ECG readings, echocardiogram findings and determination of cardiac troponin I and creatine kinase-MB levels. On the other hand, CS was established by clinical observation of features consistent with hypoperfusion, and measurements of blood pressure changes during the cardiac cycle. The PiCCO procedure was conducted by insertion of a CVP catheter and a thermodilution arterial line. These allowed for the measurement of cardiac output functions and hemodynamic parameters. Other information gathered during the study included patients’ biodata and history of prevailing comorbidities, as well as biomarkers of AMI. Additionally, details regarding the use of vasoactive agents, mechanical ventilation and length of hospitalization in the emergency and critical care units were gathered. Differences between the groups were analyzed using the SPSS 17.0 software with two-sided t-tests and chi-square tests used for continuous and categorical variables, respectively. Multiparametric analysis was performed using ANOVA and, in all cases, a P < 0.05 was considered statistically significant.
This study provides promising outcomes in the use of PiCCO among elderly patients being managed for AMI with accompanying CS. Compared to the control group, patients who received PiCCO services displayed statistically significant lower APACHE II and SOFA scores, as well as lower levels of hs-TnI and NT-proBNP. Similarly, there were generally lower lactate levels, and a diminished oxygenation index among patients in the PiCCO group on day 7 after treatment. Infusion and urine volumes were evidently higher (P < 0.01) in the PiCCO group in the first day after treatment; thereafter, no differences in these parameters were discernible on subsequent days between the two groups. There was an appreciable increase in the functional health status of patients in the PiCCO, as demonstrated by the greater ADL scores (P < 0.001). Moreover, patients in this group needed less critical care support, use of mechanical ventilation, and blood pressure modifying drugs compared to the control group (all P < 0.05). The difference in the incidence of pulmonary edema, although significantly higher among the control group, did not reach the threshold for statistical significance (P = 0.589). Considering indicators of cardiac function and vascular competence, the levels of EVLWI, ITBVI and GEDVI were all significantly lower at 48 h and 72 h as compared to 24 h after initiation of the PiCCO procedure (P < 0.001).
Our study provides clinical data that supports the need to consider applying PiCCO in managing elderly patients who have AMI that has been further confounded by CS. Improved precision in the monitoring of cardiovascular and hemodynamic changes empowers the clinician to implement appropriate and timely interventions to maintain systemic functions. Importantly, there is undisputable benefits with regards to reduced length and, by inference, cost of hospitalizations when the PiCCO technique is used. Additional positive outcomes of using PiCCO concerns the improved prognosis as manifested in better ADL scores. Based on the study findings and resources permitting, we argue for the consideration to employ the PiCCO procedure when attending to elderly patients with AMI who have also developed CS. More studies involving this technique and incorporating more, and diverse patient groups are needed to provide threshold clinical evidence that can influence future practice in managing these conditions.
Arising from the present study, it is evident that the application of PiCCO can go beyond its traditional use in septic shock and respiratory distress syndrome. Improved clinical outcomes observed among patients who received the PiCCO procedure call for conscious efforts to explore this technique more routinely among related groups of patients. For greater application, more robust data involving clinical trials in other population segments and geographical settings need to be generated to contribute to the pool of evidence in support of the utility of this method in managing AMI confounded by CS.