Utility of the PAPi for Risk Stratification in the Setting of Acute Inferior Wall Myocardial Infarction
- The presence of RV dysfunction increases the risk of CS, high-grade AV-conduction block, and higher mortality.
- The pulmonary artery pulsatility index (PAPi) is a hemodynamic measurement index which helps predict severe RV dysfunction during acute inferior wall myocardial infarction (IWMI), aiming to identify subjects requiring a percutaneous RV assist device (RVAD).
- Authors Korabathina, et.al. explored whether the PAPi correlates with severe RVD (sRVD) in acute IWMI.
- Invasive hemodynamic measurement with the PAPi may identify patients with severe RV dysfunction while predicting in-hospital mortality risk and the need for mechanical circulatory support.
- A PAPi <0.9 is highly specific and highly sensitive in identifying RV dysfunction.
The presence of RV dysfunction increases the risk of cardiogenic shock, high-grade AV-conduction block, and in-hospital mortality.1 A major cause of morbidity and mortality in acute inferior wall myocardial infarction (IWMI) can be attributed to right ventricular (RV) dysfunction. Early detection may help improve clinical outcomes in patients with RV dysfunction in the setting of acute IWMI.
Risk stratification using hemodynamic measurement tools is a necessary step toward optimizing patient care. The pulmonary artery pulsatility index (PAPi) is one such tool (calculated as the [(systolic pulmonary artery pressure – diastolic pulmonary artery pressure)/central venous pressure]). In patients in cardiogenic shock, this hemodynamic measurement index helps predict severe RV dysfunction during acute IWMI and aims to identify subjects requiring a percutaneous RV assist device (RVAD).
A retrospective study by Korabathina, et.al. examined the medical records of acute IWMI patients undergoing emergent PCI (n = 180) between 2008 and 2010.2 Only 20 patients met the inclusion criteria and were ultimately included in the final analysis. Patients suspected of having a RVD received serial electrocardiograms, intra-aortic balloon pump, and pharmacological therapy, as needed. Medications utilized in this patient population included glycoprotein IIb/IIIa receptor inhibitors, aspirin, and anticoagulants.
Researchers defined two groups for comparison: 1) patients with nonobstructive coronary artery disease ([non-CAD], n = 50), and 2) patients presenting with acute coronary syndrome requiring left coronary stenting ([ACS], n = 14).
Compared to the non-CAD the ACS group had a lower PAPi in suspected RV dysfunction (5.52 ± 4.40 vs 4.32 ± 3.04 vs 1.11 ± 0.57, respectively, P < 0.01). RV stroke work in participants with suspected RV dysfunction compared with controls (9.50 ± 8.01 vs 17.71 ± 12.24 vs 17.53 ± 10.32, respectively, P < 0.05). The PAPi showed the strongest association with estimates of RV systolic function compared with the other hemodynamic variables studied (r = -0.731, P < 0.001).
Subjects were also grouped according to clinical outcomes: 1) the need for a percutaneous RV support device (pRVSD), 2) in-hospital mortality, and 3) in-hospital mortality plus the need for any pRVSD. A decreased PAPi was consistently found among subjects with the combined outcome of in-hospital death and/or need for a pRVSD.
According to the authors, the PAPi showed the highest specificity (98.3%) and the highest sensitivity (88.9%) in the prediction of in-hospital mortality when compared to the RA:PCWP ratio and the RVSW. The PAPi also demonstrated specificity and sensitivity for predicting the need of a pRVSD with a diagnostic accuracy of 97.1%.
Hemodynamic measurements using the PAPi may provide accurate identification of patients with severe RV dysfunction and predict the need for advanced mechanical support. A receiver-operating characteristic curve analysis determined an optimal cut-point value for the PAPi of ≤0.9, with the PAPi providing 98.3% specificity and 100.0% sensitivity for the prediction of in-hospital mortality.
PAPi and RVSW values were analyzed prior to implantation and following explantation of the pRVSD to evaluate the effects of the device on hemodynamics after acute IWMI. Following explantation, there was significant hemodynamic improvement according to PAPi (0.53 ± 0.21 vs 1.10 ± 0.40, P < 0.01) and RVSW (4.06 ± 3.53 vs 12.16 ± 5.30, P < 0.01) values.
The use of invasive hemodynamic measurements with the PAPi may identify patients with severe RV dysfunction while acting as a risk stratification and prediction tool for in-hospital mortality and the need for mechanical circulatory support.
Limitations to this study included the strict inclusion criteria and the subsequent small number of patients (n = 20) enrolled in the final analysis. To arrive at a stronger conclusion, further studies regarding the prognostic capability of the PAPi for patients requiring pRVSD in significantly larger patient populations are needed.
- Mehta SR, Eikelboom JW, Natarajan MK, et al. Impact of right ventricular involvement on mortality and morbidity in patients with inferior myocardial infarction. J Am Coll Cardiol. 2001;37(1):37-43.
- Korabathina R, Heffernan KS, Paruchuri V, et al. The pulmonary artery pulsatility index identifies severe right ventricular dysfunction in acute inferior myocardial infarction. Catheter Cardiovasc Interv. 2012;80(4):593-600.
Impella® Device — Indication & Safety Information
INDICATIONS FOR USE
The Impella 2.5® and Impella CP® Systems are temporary (≤ 6 hours) ventricular support devices indicated for use during high-risk percutaneous coronary interventions (PCI) performed in elective or urgent, hemodynamically stable patients with severe coronary artery disease, when a heart team, including a cardiac surgeon, has determined high-risk PCI is the appropriate therapeutic option. Use of the Impella 2.5 and Impella CP Systems in these patients may prevent hemodynamic instability, which can result from repeat episodes of reversible myocardial ischemia that occur during planned temporary coronary occlusions and may reduce peri- and post-procedural adverse events.
The Impella 2.5®, Impella CP®, Impella 5.0®, and Impella LD® Catheters, in conjunction with the Automated Impella Controller (collectively, “Impella® System Therapy”), are temporary ventricular support devices intended for short term use (≤ 4 days for the Impella 2.5 and Impella CP, and ≤ 6 days for the Impella 5.0, and Impella LD) and indicated for the treatment of ongoing cardiogenic shock that occurs immediately (< 48 hours) following acute myocardial infarction or open heart surgery or in the setting of cardiomyopathy, including peripartum cardiomyopathy, or myocarditis as a result of isolated left ventricular failure that is not responsive to optimal medical management and conventional treatment measures (including volume loading and use of pressors and inotropes, with or without IABP). The intent of Impella System Therapy is to reduce ventricular work and to provide the circulatory support necessary to allow heart recovery and early assessment of residual myocardial function.
Important Risk Information for Impella devices
The Impella 2.5, Impella CP, Impella 5.0 and Impella LD are contraindicated for use with patients experiencing any of the following conditions: Mural thrombus in the left ventricle; Presence of a mechanical aortic valve or heart constrictive device; Aortic valve stenosis/calcification (equivalent to an orifice area of 0.6 cm2 or less); Moderate to severe aortic insufficiency (echocardiographic assessment graded as ≥ +2); Severe peripheral arterial disease precluding placement of the Impella System; Significant right heart failure*; Combined cardiorespiratory failure*; Presence of an Atrial or Ventricular Septal Defect (including post-infarct VSD)*; Left ventricular rupture*; Cardiac tamponade*
* This condition is a contraindication for the cardiogenic shock indication only.
POTENTIAL ADVERSE EVENTS
Acute renal dysfunction, Aortic valve injury, Bleeding, Cardiogenic shock, Cerebral vascular accident/Stroke, Death, Hemolysis, Limb ischemia, Myocardial infarction, Renal failure, Thrombocytopenia and Vascular injury
In addition to the risks above, there are other WARNINGS and PRECAUTIONS associated with Impella devices. Visit http://www.abiomed.com/important-safety-information to learn more.
Right-Side Support – Indication & Safety Info.
INDICATIONS FOR USE
The Impella RP® System is indicated for providing temporary right ventricular support for up to 14 days in patients with a body surface area ≥1.5 m2, who develop acute right heart failure or decompensation following left ventricular assist device implantation, myocardial infarction, heart transplant, or open-heart surgery.
Important Risk Information for Impella RP
The Impella RP System is contraindicated for patients with the following conditions: Disorders of the pulmonary artery wall that would preclude placement or correct positioning of the Impella RP device. Mechanical valves, severe valvular stenosis or valvular regurgitation of the tricuspid or pulmonary valve. Mural thrombus of the right atrium or vena cava. Anatomic conditions precluding insertion of the pump. Presence of a vena cava filter or caval interruption device, unless there is clear access from the femoral vein to the right atrium that is large enough to accommodate a 22 Fr catheter.
POTENTIAL ADVERSE EVENTS
The potential adverse effects (eg, complications) associated with the use of the Impella RP System: Arrhythmia, Atrial fibrillation, Bleeding, Cardiac tamponade, Cardiogenic shock, Death, Device malfunction, Hemolysis, Hepatic failure, Insertion site infection, Perforation, Phlegmasia cerulea dolens (a severe form of deep venous thrombosis), Pulmonary valve insufficiency, Respiratory dysfunction, Sepsis, Thrombocytopenia, Thrombotic vascular (non-central nervous system) complication, Tricuspid valve injury, Vascular injury, Venous thrombosis, Ventricular fibrillation and/or tachycardia.
In addition to the risks above, there are other WARNINGS and PRECAUTIONS associated with Impella RP®. Visit http://www.abiomed.com/impella/impella-rp to learn more.
General Indication and Safety Information
To learn more about the Impella platform of heart pumps, including important risk and safety information associated with the use of the devices, please visit: www.protectedpci.com/indications-use-safety-information/