Percutaneous Coronary Intervention For Cardiogenic Shock Research Articles

Prognostic effect of sex according to shock severity in patients with acute myocardial infarction complicated by cardiogenic shock

BackgroundSex disparities in cardiogenic shock (CS) treatment are controversial, and the prognostic implications of sex remain unclear in CS caused by acute myocardial infarction (AMI). ObjectivesThis study aimed to evaluate the prognostic effect of sex according to the severity of CS in patients undergoing percutaneous coronary intervention (PCI) for AMI complicated by CS. MethodsWe assessed 695 patients from 12 tertiary centers in South Korea who underwent PCI for AMI complicated by CS, and analyzed outcomes by sex (female [n = 184] vs. male [n = 511]). We compared a 12-month patient-oriented composite endpoint (POCE, defined as a composite of all-cause mortality, myocardial infarction, re-hospitalization due to heart failure, and repeat revascularization) between the sexes, respective of SCAI shock stage C&D or E. Propensity score-matched analysis was performed to reduce bias. ResultsWe found that the female group was older and had higher vasoactive-inotropic and IABP-SHOCK II scores than the male group, with findings consistent across SCAI shock stages. During the 12-month follow-up period, multivariate analysis revealed no significant differences in POCE (HR 1.01, 95% CI 0.67–1.53, p = 0.963 for SCAI stage C&D, HR 1.24, 95% CI 0.84–1.84, p = 0.286 for SCAI stage E) between females and males. After propensity score matching, the incidence of POCE (HR 1.47, 95% CI 0.79–2.72, p = 0.220 for SCAI stage C&D, HR 0.88, 95% CI 0.49–1.57, p = 0.665 for SCAI stage E) was similar between sexes. ConclusionsSex does not appear to influence the risk of 12-month POCE in patients treated with PCI for CS caused by AMI, irrespective of shock severity. Clinical Trial RegistrationClinicalTrials.gov NCT02985008. RESCUE (REtrospective and prospective observational Study to investigate Clinical oUtcomes and Efficacy of left ventricular assist device for Korean patients with cardiogenic shock), NCT02985008, Registered December 5, 2016 - retrospectively and prospectively. IRB InformationThis study was approved by the institutional review board of Samsung Medical Center (Reference number: 2016-03-130).

Influence of Culprit Lesion Intervention on Outcomes in Infarct-Related Cardiogenic Shock With Cardiac Arrest

BackgroundCardiac arrest (CA) is common in patients with infarct-related cardiogenic shock (CS). ObjectivesThe goal of this study was to identify the characteristics and outcomes of culprit lesion percutaneous coronary intervention (PCI) of patients with infarct-related CS stratified according to CA in the CULPRIT-SHOCK (Culprit Lesion Only PCI Versus Multivessel PCI in Cardiogenic Shock) randomized trial and registry. MethodsPatients with CS with and without CA from the CULPRIT-SHOCK study were analyzed. All-cause death or severe renal failure leading to renal replacement therapy within 30 days and 1-year death were assessed. ResultsAmong 1,015 patients, 550 (54.2%) had CA. Patients with CA were younger, more frequently male, had lower rates of peripheral artery disease, a glomerular filtration rate <30 mL/min, and left main disease, and they presented more often with clinical signs of impaired organ perfusion. The composite of all-cause death or severe renal failure within 30 days occurred in 51.2% of patients with CA vs 48.5% in non-CA patients (P = 0.39) and 1-year death in 53.8% vs 50.4% (P = 0.29), respectively. In a multivariate analysis, CA was an independent predictor of 1-year mortality (HR: 1.27; 95% CI: 1.01-1.59). In the randomized trial, culprit lesion–only PCI was superior to immediate multivessel PCI in patients both with and without CA (P for interaction = 0.6). ConclusionsMore than 50% of patients with infarct-related CS had CA. These patients with CA were younger and had fewer comorbidities, but CA was an independent predictor of 1-year mortality. Culprit lesion–only PCI is the preferred strategy, both in patients with and without CA. (Culprit Lesion Only PCI Versus Multivessel PCI in Cardiogenic Shock [CULPRIT-SHOCK]; NCT01927549)

Microaxial circulatory support for percutaneous coronary intervention: A systematic review and meta-analysis.

Microaxial circulatory support devices have been used to support patients treated with percutaneous coronary intervention (PCI) for acute myocardial infarction complicated by cardiogenic shock (AMICS). The purpose of this systematic review and meta-analysis was to pool and analyze the existing evidence on the baseline characteristics, periprocedural data, and outcomes of microaxial support before and after PCI in AMICS. An electronic database search was performed to identify all cohort studies on Impella and PCI for cardiogenic shock in the English language. A total of five articles comprising 543 patients were included. These patients received microaxial support either before (pre-PCI) or after (post-PCI) undergoing PCI. Comparative analyses were done between both groups. The mean patient age was 66 years [95% Confidence Interval (58-74)], and 22% (89/396) of patients were female. ST-elevation myocardial infarctions (MI)comprised64% (44-80) of MIs and 50% (44-56) of MIs involved the left anterior descending artery. The mean number of diseased vessels was 2.21 (1.62-2.80). The mean left ventricular ejection fraction was 31% (23.4-38.6). The mean arterial pressure was 66.3 mm Hg (54.1-78.5). Mean serum lactate [6.1 mmol/L (3.3-8.9)] and serum creatinine [1.4mg/dl (1.0-1.7)] were similar between groups. 30-day mortality was lower in the pre-PCI group [41% (34%-49%)] compared to the post-PCI group [61% (42%-77%), p< 0.01]. Pooled Kaplan-Meier analysis showed better early survival in the pre-PCI group (p< 0.001). Patients presenting with AMICS were similar at baseline in both pre-PCI and post-PCI groups. Nevertheless, pre-PCI group showed better early survival compared to post-PCI group.

Endovascular Treatment of an Elderly Diabetic Patient with a Circular Myocardial Infarction in Cardiogenic Shock Complicated by Stent Thrombosis

The most common cause of cardiogenic shock (CS) is acute myocardial infarction (AMI), which is diagnosed in approximately 5–8% of patients hospitalized for AMI and is more common in patients with acute ST-segment elevation myocardial infarction (STEMI). CS is caused by severe myocardial dysfunction, which leads to a decrease in cardiac output, hypoperfusion of the end organs, and hypoxia. Mortality in diabetic patients with AMI is high. Besides the fact that type 2 diabetes mellitus (DM2) contributes to the progression of coronary atherosclerosis, coronary pathology in this category of patients occurs against the background of a specific diabetic myocardial lesion – diabetic cardiomyopathy. Against the background of cardiomyopathy, acute heart failure is more often developed with a decrease in global myocardial contractility up to CS, which increases hospital-acquired mortality in MI by more than 15 times. The increased risk of death observed in patients with DM2 in the acute period of myocardial infarction (MI) persists for several years, and therefore, at present, in patients with the acute coronary syndrome (ACS) and diabetes, an early invasive strategy is preferable to a conservative strategy. The SHOCK (Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock) trial demonstrated that in patients with CS complicating AMI, emergency revascularization with percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) improved long-term survival when compared with initial intensive medical therapy. However, in the CULPRIT-SHOCK (Culprit Lesion Only PCI Versus Multivessel PCI in Cardiogenic Shock) study, stenting of non-infarct-dependent coronary arteries in CS increases the risks of major cardiac events, as well as the number of repeated revascularizations within 30 days and 1 year. Patients with multivessel lesions, in most cases, are elderly patients (75–90 years old) who have age restrictions on taking the loading dose at the prehospital stage. Such a loading dose of clopidogrel may not be sufficient to saturate the patient in fact, despite optimal epicardial recanalization, a large proportion of patients still experience impaired reperfusion and in-stent thrombosis. A large body of evidence has been accumulated on the benefits of glycoprotein (GP) IIb-IIIa inhibitors in terms of prevention of stent thrombosis, and benefits in mortality, especially among high-risk patients, and as an upstream strategy.

Transradial versus transfemoral approach for percutaneous coronary intervention in patients with ST-elevation myocardial infarction complicated by cardiogenic shock: a systematic review and meta-analysis.

In ST-elevation myocardial infarction (STEMI), transradial access (TRA) for percutaneous coronary intervention (PCI) is associated with less bleeding and mortality than transfemoral access (TFA). However, patients in cardiogenic shock (CS) are more often treated via TFA. The aim of this meta-analysis is to compare the safety and efficacy of TRA vs. TFA in CS. Systematic review was performed querying PubMed, Google Scholar, Cochrane, and clinicaltrials.gov for studies comparing TRA to TFA in PCI for CS. Outcomes included in-hospital, 30-day and≥1-year mortality, major and access site bleeding, TIMI3 (thrombolytics in myocardial infarction) flow, procedural success, fluoroscopy time, and contrast volume. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated using random effects models. Six prospective and eight retrospective studies (TRA, n=8032; TFA, n=23031) were identified. TRA was associated with lower in-hospital (RR 0.59, 95% CI 0.52-0.66, P&lt;0.0001), 30-day and≥1-year mortality, as well as less in-hospital major (RR 0.41, 0.31-0.56, P&lt;0.001) and access site bleeding (RR 0.42, 0.23-0.77, P=0.005). There were no statistically significant differences in post-PCI coronary flow grade, procedural success, fluoroscopy time, and contrast volume between TRA vs. TFA. In PCI for STEMI with CS, TRA is associated with significantly lower mortality and bleeding complications than TFA while achieving similar TIMI3 flow and procedural success rates.

Predictive Value of the Residual SYNTAX Score in Patients With Cardiogenic Shock

BackgroundIn hemodynamically stable patients, complete revascularization (CR) following percutaneous coronary intervention (PCI) is associated with a better prognosis in chronic and acute coronary syndromes. ObjectivesThis study sought to assess the extent, severity, and prognostic value of remaining coronary stenoses following PCI, by using the residual SYNTAX score (rSS), in patients with cardiogenic shock (CS) related to myocardial infarction (MI). MethodsThe CULPRIT-SHOCK (Culprit Lesion Only Percutaneous Coronary Intervention [PCI] Versus Multivessel PCI in Cardiogenic Shock) trial compared a multivessel PCI (MV-PCI) strategy with a culprit lesion–only PCI (CLO-PCI) strategy in patients with multivessel coronary artery disease who presented with MI-related CS. The rSS was assessed by a central core laboratory. The study group was divided in 4 subgroups according to tertiles of rSS of the participants, thereby isolating patients with an rSS of 0 (CR). The predictive value of rSS for the 30-day primary endpoint (mortality or severe renal failure) and for 30-day and 1-year mortality was assessed using multivariate logistic regression. ResultsAmong the 587 patients with an rSS available, the median rSS was 9.0 (interquartile range: 3.0 to 17.0); 102 (17.4%), 100 (17.0%), 196 (33.4%), and 189 (32.2%) patients had rSS = 0, 0 < rSS ≤5, 5 < rSS ≤14, and rSS >14, respectively. CR was achieved in 75 (25.2%; 95% confidence interval [CI]: 20.3% to 30.5%) and 27 (9.3%; 95% CI: 6.2% to 13.3%) of patients treated using the MV-PCI and CLO-PCI strategies, respectively. After multiple adjustments, rSS was independently associated with 30-day mortality (adjusted odds ratio per 10 units: 1.49; 95% CI: 1.11 to 2.01) and 1-year mortality (adjusted odds ratio per 10 units: 1.52; 95% CI: 1.11 to 2.07). ConclusionsAmong patients with multivessel disease and MI-related CS, CR is achieved only in one-fourth of the patients treated using an MV-PCI strategy. and the residual SYNTAX score is independently associated with early and late mortality.

Impact of chronic total occlusion and revascularization strategy in patients with infarct-related cardiogenic shock: A subanalysis of the culprit-shock trial

The impact of coronary artery chronic total occlusion (CTO) and its management with percutaneous coronary intervention (PCI) in the setting of myocardial infarction (MI) related cardiogenic shock (CS) remains unclear. This is a pre-specified analysis from the culprit-lesion-only PCI vs multivessel PCI in CS (CULPRIT-SHOCK) trial which randomized patients presenting with MI and multivessel disease complicated by CS to a culprit-lesion-only or immediate multivessel PCI strategy. CTO was defined by central core-laboratory evaluation. The independent associations between the presence of CTO and adverse outcomes at 30 days and 1 year were assessed using multivariate logistics models. A noninfarct related CTO was present in 157 of 667 (23.5%) analyzed patients. Patients presenting with CTO had more frequent diabetes mellitus or prior PCI but less frequently presented with ST segment elevation MI as index event. The presence of CTO was associated with higher rate of death at 30 days (adjusted Odds ratio 1.63; 95% confidence interval [CI] 1.01-2.60). Rate of death at 1 year was also increased but did not reach statistical significance (adjusted Odds ratio 1.62; 95%CI 0.99-2.66). Compare to immediate multivessel PCI, a strategy of culprit-lesion-only PCI was associated with lower rates of death or renal replacement therapy at 30 days in patients with and without CTO (Odds ratio 0.79 95%CI 0.42-1.49 and Odds ratio 0.67 95%CI 0.48-0.96, respectively), without significant interaction (P = .68). In patients with MI-related CS and multivessel disease, the presence of CTO is associated with adverse outcomes while a strategy of culprit-lesion-only PCI seems beneficial regardless of the presence of CTO.

Prognostic Value of SYNTAX Score in Patients With Infarct-Related Cardiogenic Shock: Insights From the CULPRIT-SHOCK Trial

ObjectivesThis study sought to evaluate the prognostic value of the SYNTAX (SYNergy between PCI with TAXUS and Cardiac Surgery) scores in patients undergoing percutaneous coronary intervention (PCI) for multivessel coronary disease with infarct-related cardiogenic shock (CS). BackgroundThe prognostic value of the SYNTAX score in this high-risk setting remains unclear. MethodsThe CULPRIT-SHOCK (Culprit Lesion Only PCI versus Multivessel PCI in Cardiogenic Shock) trial was an international, open-label trial, where patients presenting with infarct-related CS and multivessel disease were randomized to a culprit-lesion-only or an immediate multivessel PCI strategy. Baseline SYNTAX score was assessed by a central core laboratory and categorized as low SYNTAX score (SS ≤22), intermediate SYNTAX score (22<SS≤32) and high SYNTAX score (SS>32). Adjudicated endpoints of interest were the 30-day risk of death or renal replacement therapy (RRT) and 1-year death. Associations between baseline SYNTAX score and outcomes were assessed using multivariate logistic regression. ResultsPre-PCI SYNTAX score was available in 624 patients, of whom 263 (42.1%), 207 (33.2%) and 154 (24.7%) presented with low, intermediate and high SYNTAX score, respectively. A stepwise increase in the incidence of adverse events was observed from low to intermediate and high SYNTAX score for the 30-day risk of death or RRT and the 1-year risk of death (p < 0.001, for all). After multiple adjustments, intermediate and high SYNTAX score remained strongly associated with 30-day risk of death or renal replacement therapy and 1-year risk of all-cause death. There was no significant interaction between SYNTAX score and the coronary revascularization strategy for any outcomes. ConclusionsIn patients presenting with multivessel disease and infarct-related CS, the SYNTAX score was strongly associated with 30-day death or RRT and 1-year mortality.

Non-pharmaco, non-invasive management of coronary no-reflow phenomenon.

IntroductionNo-reflow is an infrequent but dreaded complication of percutaneous coronary intervention (PCI), where the culprit is obstruction of the downstream microvascular bed. The aim of this study was to evaluate the efficacy and safety of forceful injection of blood (autologous blood transfusion – ABT) in reversing no-reflow during PCI because data regarding its effectiveness is not available.Material and methods100–120 ml of blood was withdrawn through guiding catheter over 3 to 5 min using a 10 ml syringe and re-infused by forceful injection over 3 min through it, and its efficacy was assessed at 10 min using TIMI flow grade and quantitative corrected TIMI frame count.ResultsIn total 93 patients received ABT following no-reflow. Their clinical presentation was ST-elevation myocardial infarction (STEMI) (n = 61; 65.6%), non-ST-elevation myocardial infarction (NSTEMI) (n = 23; 24.7%), and unstable angina (n = 9; 9.6%). It was observed among patients undergoing primary PCI (n = 18; 19.3%), pharmaco-invasive PCI (n = 27; 29%), rescue PCI (n = 11; 11.8%), and PCI for cardiogenic shock (n = 5; 5.3%). A mean volume of 108 ±4 ml blood was transfused. Commonest culprit vessel was left anterior descending artery (n = 51; 54.8%) followed by right coronary (n = 29; 31.2%), left circumflex (n = 19; 10.8%), and saphenous vein grafts (n = 3; 3.2%). Following ABT, TIMI 3 flow was successfully restored in 77 (82.7%) patients. TIMI flow grade improved from 1.02 to 2.52 and cTIMI frame count decreased from 60.6 ±12 to 16.1 ±6 (p < 0.001). ABT was well tolerated except transient hypotension (n = 17; 18.3%). Overall mortality was reported in 10 (10.7%) patients at 1 year.ConclusionsIn this largest and only study to date, ABT is a safe and highly effective approach to reverse no-reflow by raising driving pressure across the capillary bed.

CULPRIT-SHOCK (Culprit Lesion Only PCI Versus Multivessel Percutaneous Coronary Intervention in Cardiogenic Shock): Implications on Guideline Recommendations.

Mortality of cardiogenic shock complicating myocardial infarction can be reduced by an early invasive strategy with percutaneous coronary intervention (PCI) of the infarct-related artery. Up to 80% of patients with cardiogenic shock present with multivessel coronary artery disease, and their mortality is higher compared with patients with single-vessel disease. Until recently, there were no randomized data on how to deal with nonculprit lesions in the setting of cardiogenic shock. This lack of evidence is also reflected by divergent recommendations in current international guidelines. The European ST-segment–elevation acute myocardial infarction (STEMI) guidelines, published in 2017, recommend immediate PCI of nonculprit lesions in patients with cardiogenic shock (Class IIb, Level of Evidence C),1 whereas the American STEMI guidelines give no specific recommendation.2 However, American appropriate use criteria, also published in 2017, consider immediate revascularization of a nonculprit artery during the same procedure appropriate if cardiogenic shock persists after treatment of the culprit artery.3 After publication of the randomized, multicenter CULPRIT-SHOCK trial (Culprit Lesion Only PCI Versus Multivessel PCI in Cardiogenic Shock), guidelines and appropriate use criteria need to be reconsidered. To briefly recap, CULPRIT-SHOCK showed a significant clinical benefit of a culprit-lesion-only strategy with a reduction in the primary end point of 30-day mortality or severe renal failure requiring renal replacement therapy (45.9% culprit-lesion-only PCI versus 55.4% immediate multivessel PCI group; relative risk, 0.83; 95% confidence interval, 0.71–0.96; P =0.01), which was driven mainly by an absolute 8.2% reduction in 30-day mortality (43.3% versus 51.5%; relative risk, 0.84; 95% confidence interval, 0.72–0.98; P =0.03).4 With the application of current guideline criteria, the results …

Transradial Artery Access in Percutaneous Coronary Intervention for ST-Segment Elevation Myocardial Infarction and Cardiogenic Shock.

Early revascularization is the gold standard for management of patients with ST-elevation myocardial infarction (STEMI) and cardiogenic shock (CS). The use of transradial artery access (TRA) in percutaneous coronary intervention (PCI) has increased in recent years and has emerged as a safe and effective approach to PCI in high-risk patients, with advantages in reduced major bleeding events, other peri-procedural complications, and all-cause mortality when compared with transfemoral artery access (TFA). Multiple randomized clinical trials have demonstrated these advantages of TRA vs. TFA PCI in STEMI patients. Although there remains a lack of dedicated randomized trials in CS, observational data suggest benefits on the same endpoints as in STEMI with TRA vs. TFA PCI in CS. This review summarizes the existing literature on the use of TRA compared to TFA for STEMI and CS patients; the reduction of major bleeding events, other peri-procedural complications, and mortality associated with TRA in STEMI and CS; and technical considerations and challenges in the care of these high-risk patient populations.

Long-Term Outcomes After Percutaneous Coronary Intervention (PCI) to an Unprotected Left Main Coronary Artery (LMCA) in Cardiogenic Shock: Observations From the Melbourne Interventional Group (MIG) Registry

Background: Recent trials support the use of PCI with drug eluting stents as an alternative to coronary artery bypass grafting (CABG) in selected stable patients. In cardiogenic shock, urgent revascularisation is optimal. We review the MIG experience on unprotected LMCA PCI in cardiogenic shock. Method: Excluding patients with previous bypass surgery, consecutive patients presenting with cardiogenic shock undergoing PCI from the MIG registry between 2005-2016 were analysed, comparing those with LMCA PCI to non-LMCA PCI. Results: A total of 601 patients (3.2% of all PCI patients without previous CABG) presented in cardiogenic shock. 45 (7.5%) patients had unprotected LMCA PCI. Patients undergoing unprotected LMCA PCI were older (70.1years vs 65.8years, p = 0.01) with the same rate of male predominance (77.8% vs 72.1%, p = 0.75), hypertension (70.5% vs 56.8%, p = 0.08), diabetes (22.7% vs 24.6%, p = 0.78) and hypercholesterolaemia (52.3% vs 47.1%, p = 0.51). In cardiogenic shock, the in hospital mortality with unprotected LMCA PCI is 64.4% compared to 36.5% with non LMCA PCI, with long-term mortality linked to the national death index (NDI) in the LMCA PCI group being 80.0%. Unprotected LMCA PCI in the setting of cardiogenic shock is an independent predictor of long-term mortality (HR 1.59, 95% CI 1.003-2.527, p = 0.048). Conclusion: Outcomes after PCI to unprotected LMCA in cardiogenic shock are poor, with the excess in mortality occurring early. It may be beneficial for on table discussions regarding urgent coronary bypass grafting in this setting.

Editor's Choice- Impact of immediate multivessel percutaneous coronary intervention versus culprit lesion intervention on 1-year outcome in patients with acute myocardial infarction complicated by cardiogenic shock: Results of the randomised IABP-SHOCK II trial.

Current guidelines recommend immediate multivessel percutaneous coronary intervention (PCI) in patients with cardiogenic shock, despite the lack of randomised trials. We sought to investigate the use and impact on outcome of multivessel PCI in comparison to culprit lesion only PCI in a retrospective analysis in patients with cardiogenic shock complicating acute myocardial infarction. In the randomised IABP-SHOCK II trial, investigating the effect of intra-aortic balloon pump on outcome, 451 (75%) of the total of 600 patients had multivessel coronary artery disease and underwent PCI. Immediate multivessel PCI was performed in 167 (37%) patients. TIMI 3 patency after PCI in all treated vessels was observed in 83.2% versus 79.0% of patients after multivessel versus culprit lesion PCI, respectively. The 30-day (44.9% vs. 42.3%) and 12-month (54.8% vs. 52.7%) mortality rates did not significantly differ between the two groups. In the multivariate analysis multivessel PCI was not associated with an improved mortality after 12 months (odds ratio 0.92, 95% confidence intervals 0.69-1.21). In this retrospective analysis of the largest randomised study in cardiogenic shock immediate multivessel PCI was used in approximately one third of patients with cardiogenic shock. There was no benefit with immediate multivessel PCI in comparison to culprit lesion only PCI. Therefore a randomised trial is needed to determine the definitive role of multivessel PCI in cardiogenic shock. ClinicalTrials.gov , NCT00491036.

UTILIZATION OF MECHANICAL CIRCULATORY SUPPORT IN PATIENTS UNDERGOING PERCUTANEOUS CORONARY INTERVENTION: INSIGHTS FROM THE NCDR

Limited data is available on contemporary use of intra-aortic balloon pump (IABP) and other mechanical circulatory support (O-MCS) devices in patients undergoing percutaneous coronary intervention (PCI) with cardiogenic shock (CS). Patients undergoing PCI in CS at 1,429 NCDR CathPCI® participating

Intra-aortic balloon pump for high-risk percutaneous coronary intervention.

The intra-aortic balloon pump (IABP) was first introduced into clinical practice in 1968.1 Early experimental and clinical trials suggested that intra-aortic balloon counterpulsation could provide circulatory assistance to a failing left ventricle.2,3 Counterpulsation—balloon inflation during diastole and deflation in systole—augments the intrinsic Windkessel effect, whereby potential energy stored in the aortic root during systole is converted to kinetic energy with the elastic recoil of the aortic root. Counterpulsation leads to a decline in afterload, a reduction in cardiac work, and therefore myocardial oxygen requirements of the ventricle. Augmentation of diastolic pressure when the balloon is fully inflated together with reduction in left ventricular (LV) filling pressures contribute to improved coronary perfusion (Figures 1 and 2).4 This proposed improvement in myocardial energetics has been further supported by a significant reduction in systemic lactate.5 These physiological enhancements are thought to be of particular benefit after acute myocardial infarction (AMI), supported by animal studies, which have shown a reduction in infarct size when counterpulsation is used.6,7 Figure 1. Coronary perfusion. Coronary flow is predominantly diastolic and further enhanced by counterpulsation, which augments diastolic blood flow and thus coronary perfusion. In addition, aortic recoil during diastole further improves efficiency of the left ventricle. Figure 2. Systemic arterial pressure waveform on introduction of intra-aortic balloon pump–assisted diastolic augmentation. The intra-aortic balloon pump inflates at the dicrotic notch, leading to peak-augmented diastolic pressure. As the balloon deflates, assisted end diastolic pressure is seen to be lower than unassisted end diastolic pressure and assisted systolic pressure is lower than unassisted systolic pressure. Peak diastolic augmentation should be greater than the unassisted systolic pressure and both assisted pressures should be less than the unassisted pressures. Intra-aortic balloon counterpulsation was initially used as a means of supporting patients undergoing surgical revascularization. Percutaneous delivery …