Culprit or multivessel revascularisation in ST-elevation myocardial infarction with cardiogenic shock

Contemporary Functional Coronary Angiography: An Update

Functional coronary angiography (FCA) is a novel modality for assessing the physiology of coronary lesions, going beyond anatomical visualization by traditional coronary angiography. FCA incorporates indices like fractional flow reserve (FFR) and instantaneous wave-free ratio (IFR), which utilize pressure measurements across coronary stenoses to evaluate hemodynamic impacts and to guide revascularization strategies. In this review, we present traditional and evolving modalities and uses of FCA. We will also evaluate the existing evidence and discuss the applicability of FCA in various clinical scenarios. Finally, we provide insight into emerging evidence, current challenges, and future directions in FCA.

Outcomes of patients with myocardial infarction and cardiogenic shock treated with culprit vessel-only versus multivessel primary PCI

INTRODUCTION AND OBJECTIVES

Multivessel primary percutaneous coronary intervention (pPCI) is still often used in patients with ST-elevation myocardial infarction (STEMI) and cardiogenic shock (CS). The study aimed to compare the characteristics and prognosis of patients with CS-STEMI and multivessel coronary disease (MVD) treated with culprit vessel-only pPCI or multivessel-pPCI during the initial procedure.

MATERIAL AND METHODS

From 2016 to 2020, 23,703 primary PCI patients with STEMI were included in a national all-comers registry of cardiovascular interventions. Of them, 1,213 (5.1%) patients had CS and MVD at admission to the hospital. Initially, 921 (75.9%) patients were treated with culprit vessel (CV)-pPCI and 292 (24.1%) with multivessel (MV)-pPCI.

RESULTS

Patients with 3-vessel disease and left main disease had a higher probability of being treated with MV-pPCI than patients with 2-vessel disease and patients without left main disease (28.5% vs. 18.6%; p < 0.001 and 37.7% vs. 20.6%; p < 0.001). Intra-aortic balloon pump, extracorporeal membrane oxygenation (ECMO), and other mechanical circulatory support systems were more often used in patients with MV-pPCI. Thirty (30)-day and 1-year all-cause mortality rates were similar in the CV-pPCI and MV-pPCI groups (odds ratio, 1.01; 95% confidence interval [CI] 0.77 to 1.32; p = 0.937 and 1.1; 95% CI 0.84 to 1.44; p = 0.477). The presence of 3-vessel disease and the use of ECMO were the strongest adjusted predictors of 30-day and 1-year mortality.

CONCLUSIONS

Our data from an extensive all-comers registry suggests that selective use of MV-pPCI does not increase the all-cause mortality rate in patients with CS-STEMI and MVD compared to CV-pPCI.

ST Elevation Myocardial Infarction Complicated by Cardiogenic Shock: Systematic Review of Survival Predictors

Background

Cardiogenic shock complicating acute myocardial infarction is associated with reduced survival despite advancements in the treatment of acute coronary syndromes. Characterizing predictors of morbidity and mortality in this setting is crucial to improving risk stratification and management. Notwithstanding, the interplay of factors determining survival in this condition remains poorly studied.

Methods

Embase, MEDLINE, and CINAHL databases were searched for original studies evaluating predictors of short-term (30-day or in-hospital) survival in ST elevation myocardial infarction with cardiogenic shock (STEMI-CS). Included studies were analyzed by way of vote counting, identifying variables that predicted mortality or survival.

Results

Twenty-four studies, consisting of 14,735 patients (5649 nonsurvivors and 9086 survivors) were included. All studies were observational by design (17 retrospective and 7 prospective) with clinical and statistical heterogeneity. Unsuccessful revascularization, reduced left ventricular ejection fraction, renal impairment, and other variables were identified as key independent predictors of mortality.

Conclusion

Several key variables have been shown to independently increase mortality in STEMI-CS populations. Future prospective studies examining the prognostic role of multivariate scoring systems incorporating these domains are required.

Multivessel vs. culprit-vessel only percutaneous coronary interventions in acute myocardial infarction and cardiogenic shock: a systematic review and meta-analysis of prospective randomized and retrospective studies

AIMS

Studies comparing outcomes of multivessel (MV) vs. culprit-vessel (CV) only percutaneous coronary intervention (PCI) during index cardiac catheterization in patients presenting with acute myocardial infarction (MI) and cardiogenic shock (CS) have reported conflicting results. In this systematic review we aim to investigate outcomes with MV vs. CV-only revascularization strategies in patients with acute MI and CS.

METHODS AND RESULTS

PubMed, Google Scholar, CINAHL and Cochrane databases were queried for studies comparing MV vs. CV PCI in patients with acute MI and CS. Data were extracted and pooled by means of random effects model. Primary outcome was early all-cause mortality (up to 30 days), while the secondary outcomes included late all-cause mortality (mean, 11.4 months), stroke, new renal replacement therapy, reinfarction, repeat revascularization, and bleeding. Pooled odds ratio (OR), 95% confidence intervals (CIs), and number needed to harm (NNH) were calculated. A total of 16 studies enrolling 75  431 patients were included. The MV PCI was associated with higher risk of early mortality [OR 1.17, 95% CI (1.00-1.35); P = 0.04; NNH = 62], stroke [1.15 (1.03-1.29); P = 0.01; NNH = 351], and new renal replacement therapy [1.33 (1.06-1.67); P = 0.01; NNH = 61]; and with lower risk of repeat revascularization [0.61 (0.41-0.89); P = 0.01] when compared with CV PCI. No significant difference was observed in late-term mortality [1.02 (0.84-1.25); P = 0.84], risk of reinfarction [1.13 (0.94-1.35); P = 0.18], or bleeding [1.21 (0.94-1.55); P = 0.13] between groups.

CONCLUSION

Among patients with acute MI and CS, MV PCI during index cardiac catheterization was associated with higher risk of early mortality, stroke, and renal replacement therapy.

Multivessel vs. Culprit Vessel-Only Percutaneous Coronary Intervention for ST-Segment Elevation Myocardial Infarction in Patients With Cardiogenic Shock: An Updated Systematic Review and Meta-Analysis

Background

The optimal revascularization strategy in patients with ST-segment elevation myocardial infarction (STEMI) complicating by cardiogenic shock (CS) remains controversial. This study aims to evaluate the clinical outcomes of multivessel percutaneous coronary intervention (MV-PCI) compared to culprit vessel-only PCI (CO-PCI) for the treatment, only in patients with STEMI with CS.

Methods

A comprehensive literature search was conducted. Studies assessed the efficacy outcomes of short (in-hospital or 30 days)/long-term mortality, cardiac death, myocardial reinfarction, repeat revascularization, and safety outcomes of stroke, bleeding, acute renal failure with MV-PCI vs. CO-PCI in patients with STEMI with CS were included. The publication bias and sensitivity analysis were also performed.

Results

A total of 15 studies were included in this meta-analysis. There was no significant difference in short- and long-term mortality in patients treated with MV-PCI compared to CO-PCI group [odds ratio (OR) = 1.17; 95% confidence interval (CI), 0.92–1.48; OR = 0.86; 95% CI, 0.58–1.28]. Similarly, there were no significant differences in cardiac death (OR = 0.67; 95% CI, 0.44–1.00), myocardial reinfarction (OR = 1.24; 95% CI, 0.77–2.00), repeat revascularization (OR = 0.75; 95% CI, 0.40–1.42), bleeding (OR = 1.53; 95% CI, 0.53–4.43), or stroke (OR = 1.42; 95% CI, 0.90–2.23) between the two groups. There was a higher risk in acute renal failure (OR = 1.33; 95% CI, 1.04–1.69) in patients treated with MV-PCI when compared with CO-PCI.

Conclusion

This meta-analysis suggests that there may be no significant benefit for patients with STEMI complicating CS treated with MV-PCI compared with CO-PCI, and patients are at increased risk of developing acute renal failure after MV-PCI intervention.

Acute Myocardial Infarction of the Left Main Coronary Artery Presenting with Cardiogenic Shock and Pulmonary Edema during Noncardiac Surgery

Acute myocardial infarction (AMI) caused by severe stenosis of left main coronary artery (LMCA) presenting with cardiogenic shock and pulmonary edema during noncardiac surgery is uncommon, but a catastrophic event. A 77-year-old male with cholangiocarcinoma underwent hepatectomy. During the surgery, he presented with cardiogenic shock, which did not respond to infusion administration or vasopressor. A transesophageal echocardiogram revealed anterior, septal, and lateral severe hypokinesia and impaired left ventricular function. Emergent coronary angiogram showed severe stenosis of LMCA. The patient underwent primary percutaneous coronary intervention (PCI) under the support of intra-aortic balloon pump, followed by extracorporeal membrane oxygenation. The chest roentgenogram showed pulmonary edema. Two days after PCI, he successfully underwent hepatectomy and bile duct resection. Early identification of the cause of hemodynamic instability during noncardiac surgery and invasive strategy are important for minimizing the myocardial injury and improving clinical outcomes in AMI of LMCA.

Does multivessel revascularization fit all patients with STEMI and multivessel coronary artery disease? A systematic review and meta-analysis

Objective

We sought to assess the relative merits of different revascularization strategies in patients with ST-segment elevation myocardial infarction (STEMI) and multivessel coronary artery disease complicated by cardiogenic shock or chronic total occlusion (CTO).

Background

Recent randomized trials and meta-analysis have suggested that multivessel percutaneous coronary intervention (PCI) is associated with better outcomes in patients with STEMI and multivessel coronary artery disease, however, patients complicated by cardiogenic shock or CTO were excluded.

Methods

Studies that compared multivessel PCI (immediate or staged) with culprit-only PCI in patients with STEMI and multivessel coronary artery disease complicated by cardiogenic shock or CTO were included. Random odd ratio (OR) and 95% confidence interval (CI) were conducted.

Results

Sixteen studies with 8695 patients complicated by cardiogenic shock and eight studies with 2259 patients complicated by CTO were included. In patients complicated by cardiogenic shock, a strategy of CO-PCI was associated with lower risk for short-term renal failure (OR: 0.75; 95% CI: 0.61–0.93; I² = 0.0%), with no significant difference in MACE, all-cause mortality, re-infarction, revascularization, cardiac death, heart failure, major bleeding, or stroke compared with an immediate MV-PCI strategy. In patients complicated by CTO, a strategy of CO-PCI was associated with higher risk for long-term MACE (OR: 2.06; 95% CI: 1.39–3.06; I² = 54.0%), all-cause mortality (OR: 2.89; 95% CI: 2.09–4.00; I² = 0.0%), cardiac death (OR: 3.12; 95% CI: 2.05–4.75; I² = 16.8%), heart failure (OR: 1.99; 95% CI: 1.22–3.24; I² = 0.0%), and stroke (OR: 2.80; 95% CI: 1.04–7.53; I² = 0.0%) compared with a staged MV-PCI strategy, without any difference in re-infarction, revascularization, or major bleeding.

Conclusions

For patients with STEMI and multivessel coronary artery disease complicated by cardiogenic shock, an immediate multivessel PCI was not advocated due to a higher risk for short-term renal failure, whereas for patients complicated by CTO, a staged multivessel PCI was advocated due to reduced risks for long-term MACE, all-cause mortality, cardiac death, heart failure, and stroke.

Multivessel Versus Culprit-Vessel Percutaneous Coronary Intervention in Patients With Non-ST-Segment Elevation Myocardial Infarction and Cardiogenic Shock

OBJECTIVES

The aim of this study was to compare in-hospital outcomes and long-term mortality of multivessel versus culprit vessel-only percutaneous coronary intervention (PCI) in patients with non-ST-segment elevation myocardial infarction (NSTEMI), multivessel disease (MVD) and cardiogenic shock.

BACKGROUND

The clinical benefits of complete revascularization in patients with NSTEMI, MVD, and cardiogenic shock remain uncertain.

METHODS

Among 25,324 patients included in the National Cardiovascular Data Registry CathPCI Registry from July 2009 to March 2018, the rates of in-hospital procedural outcomes were compared between those undergoing multivessel PCI and those undergoing culprit vessel-only PCI after 1:1 propensity score matching. Among patients aged ≥65 years matched to the Centers for Medicare and Medicaid Services database, long-term mortality was compared using proportional hazards analysis.

RESULTS

Multivessel PCI was performed in 9,791 patients (38.7%), which increased from 32.2% in 2010 to 44.2% in 2017 (p for trend <0.001). After 1:1 propensity matching (n = 7,864 in each group), those undergoing multivessel PCI had a 3.5% (95% confidence interval [CI]: 2.0% to 5.0%) lower absolute rate of in-hospital mortality (30.9% vs. 34.4%; p < 0.001; odds ratio [OR]: 0.85; 95% CI: 0.80 to 0.91), but a higher risk for bleeding (13.2% vs. 10.8%; p < 0.001; OR: 1.26; 95% CI: 1.15 to 1.40) and new requirement for dialysis (5.7% vs. 4.6%; p = 0.001; OR: 1.26; 95% CI: 1.10 to 1.46). Among those surviving to discharge, all-cause mortality was similar through 7 years (conditional hazard ratio: 0.95; 95% CI: 0.87 to 1.03; p = 0.20).

CONCLUSIONS

Nearly 40% of patients with NSTEMI with MVD and cardiogenic shock underwent multivessel PCI, which was associated with lower in-hospital mortality but greater peri-procedural complications. Among those surviving to discharge, multivessel PCI did not confer additional long-term mortality benefit.

Multivessel Intervention in Myocardial Infarction with Cardiogenic Shock: CULPRIT-SHOCK Trial Outcomes in the PL-ACS Registry

Background: The aim of the study was a comparison of culprit-lesion-only (CL-PCI) with the multivessel percutaneous coronary intervention (MV-PCI) in terms of 30-day and 12-month mortality in a national registry. Methods: Patients from the PL-ACS registry with MI and CS were analyzed. Patients meeting the criteria of the CULPRIT-SHOCK trial were divided into two groups: CL-PCI and MV-PCI groups. Results: Of the 3265 patients in the PL-ACS registry with MI complicated by CS, the criteria of the CULPRIT-SHOCK trial were met by 2084 patients (63.8%). The CL-PCI was performed in 883 patients, and MV-PCI was performed in 1045 patients. After the propensity score matching analysis, 617 well-matched pairs were obtained. In a 30-day follow-up, death from any cause occurred in 49.3% in the CL-PCI group and 57.0% in the MV-PCI group (RR 0.86, 95% CI 0.58–0.92, p = 0.0081). After 12 months, the rate of mortality was 62.5% in the CL-PCI group and 68.0% in the MV-PCI group (RR 0.92, 95% CI 0.84–1.01, p = 0.066). Conclusions: The results confirm the validity of CULPRIT-SHOCK findings in a national registry and current guideline-recommended strategy of revascularization limited to the infarct-related artery.

Management of ST-Elevation Myocardial Infarction in High-Risk Settings

Despite the widespread adoption of primary percutaneous intervention and modern antithrombotic therapy, ST-segment elevation myocardial infarction (STEMI) remains the leading cause of death in the United States and remains one of the most important causes of morbidity and mortality worldwide. Certain high-risk patients present a challenge for diagnosis and treatment. The widespread adoption of primary percutaneous intervention in addition to modern antithrombotic therapy has resulted in substantial improvement in the short- and long-term prognosis following STEMI. In this review, we aim to provide a brief analysis of the state-of-the-art treatment for patients presenting with STEMI, focusing on cardiogenic shock, current treatment and controversies, cardiac arrest, and diagnosis and treatment of mechanical complications, as well as multivessel and left main-related STEMI.

Long-Term Mortality Comparison of Patients With Acute Myocardial Infarction Complicated by Cardiogenic Shock and Treated With Culprit-Only or Multivessel Percutaneous Coronary Intervention

OBJECTIVES

We sought to determine whether, in a real word context of patients with Acute Myocardial Infarction (AMI), multivessel disease (MVD) and cardiogenic shock (CS), the successful treatment with primary percutaneous coronary intervention (p-PCI) of only culprit lesions (OC-PCI) is associated with better long-term mortality rates than multivessel PCI (MV-PCI) of all significant lesions.

METHODS

From our registry of all consecutive patients admitted for AMI between January 1995 and December 2016 we selected those presenting with CS and MVD successfully treated with p-PCI, and compared those who underwent OC-PCI against MV-PCI, either during the p-PCI (MV-pPCI) or by staged revascularization (Staged-PCI) during hospitalization. The primary endpoint was 2-year all-cause death.

RESULTS

Among 4210 patients with AMI, 406 (9.6%) presented CS (Killip class IV). A total of 292 patients had MVD. Of them, 252 (86.3%) were successfully treated with p-PCI, 159 patients with OC-PCI and 93 with MV-PCI, either in the same (n = 29) or staged procedure (n = 64). At 2-year follow-up the overall mortality was 47.6%, lower in MV-PCI group (37.6% vs 53.5% in OC-PCI, p = 0.019). Diabetes (HR = 1.50, 1.01-2.22), three vessel disease (HR = 1.49, 1.02-2.17) and basal left ventricular ejection fraction <15% (HR = 3.39, 2.41-6.27) were independent predictors of mortality, while MV-PCI was the only variable associated with improved survival (HR = 0.54, 0.36-0.81).

CONCLUSIONS

In this real world registry of AMI patients with MVD presenting CS, MV-PCI was associated with better long-term survival.

Utilization and Outcomes of Temporary Mechanical Circulatory Support Devices in Cardiogenic Shock

Cardiogenic shock (CS) is associated with high morbidity and mortality despite recent advances in the temporary mechanical circulatory support (MCS) devices. The current utilization and outcomes of these MCS devices with or without vasopressors compared with conventional medical therapy (no-MCS) in CS remain poorly described. The study population was extracted from the 2014 Nationwide Readmissions Database using International Classification of Diseases, Ninth Revision, Clinical Modification codes for CS, temporary MCS devices, and vasopressor infusion. Study end points included in-hospital all-cause mortality, length of index hospital stay (LOS), the likelihood of receiving invasive treatment, postprocedural bleeding, vascular complications, total hospitalization charges, and discharge disposition. A total of 59,148 discharges with a diagnosis of CS were identified (age 67 years; 38.5% female). Temporary MCS devices were utilized in 22.7%. The use of these devices was associated with lower in-hospital all-cause mortality (33.0% vs 39.7%, p <0.01), increased likelihood of invasive therapy (75.7% vs 26.3%, p <0.01), and increased likelihood of being discharged home (24.8% vs 20.6%, p <0.01). However, the MCS group had longer LOS (16.9 vs 12.1 days, p <0.01), higher vascular complications (2.6% vs 1.4%, p <0.01), bleeding (31.2% vs 16.8%, p <0.01), and total hospitalization charges ($374,574 vs $182,045, p <0.01). In conclusion, the use of the temporary MCS devices for the treatment of CS was associated with lower mortality, increased the likelihood of receiving invasive treatment and the likelihood of being discharged home. However, it was associated with higher in-hospital complications, LOS, and hospitalization charges.

Cardiogenic Shock Following Acute Myocardial Infarction: What's New?

Cardiogenic shock (CS) is a state of critical end-organ hypoperfusion primarily due to cardiac dysfunction. This condition is the most common cause of death in patients affected by acute myocardial infarction (AMI). Despite early revascularization, prompt optimal medical therapy, and up-to-date mechanical circulatory supports, mortality of patients with CS remains high.The objective of this review is to summarize epidemiology, pathophysiology, and treatment options of CS in light of the new European Society of Cardiology (ESC) recommendations. The latest European guidelines on myocardial revascularization have reviewed the previous guidelines with respect to early multivessel revascularization and routine use of intra-aortic balloon pump (IABP) in patients with AMI-related CS.Most of the current evidences come partly from randomized trials, but mostly from observational registries because of the difficulty to test different treatments in this life-threatening clinical setting.Some of the latest studies highlight the potential crucial benefit of newly introduced mechanical circulatory support devices, although evidences are not sufficient to definitely assess the benefit/risk ratio of the different systems.Many questions remain unanswered in this field, and further trials are advocated to better elucidate the best medical, reperfusion, and circulatory support approaches aimed to improve the poor prognosis of patients with CS after AMI.

Meta-analysis Comparing Culprit Vessel Only Versus Multivessel Percutaneous Coronary Intervention in Patients With Acute Myocardial Infarction and Cardiogenic Shock

Cardiogenic shock (CS) after a myocardial infarction continues to be associated with high mortality. Whether percutaneous coronary intervention (PCI) of noninfarct coronary arteries (multivessel intervention [MVI]) improves outcomes in CS after acute myocardial infarction (AMI) remains controversial. MEDLINE, Cochrane CENTRAL, and Scopus databases were searched for original studies comparing MVI with culprit-vessel intervention (CVI) in AMI patients with multivessel disease and CS. Risk ratios (RRs) and 95% confidence intervals were calculated and pooled using a random effects model. Thirteen studies, consisting of 7,906 patients (n_MVI = 1,937; n_CVI = 5,969), were included in this meta-analysis. Overall, the MVI and CVI groups did not differ significantly in the risk of short-term mortality (RR: 1.06 [0.91, 1.23]; p = 0.45; I² = 75.82%), long-term mortality (RR: 0.93 [0.78, 1.11]; p = 0.37; I² = 67.92%), reinfarction (RR: 1.16 [0.75, 1.79]; p = 0.50; I² = 0%), revascularization (RR: 0.84 [0.48, 1.47]; p = 0.54; I² = 83.01%), bleeding (RR: 1.15 [0.96, 1.38]; p = 0.09, I² = 0%), or stroke (RR: 1.29 [0.86, 1.94]; p = 0.80, I² = 0%). However, significantly increased risk of renal failure was seen in the MVI group (RR: 1.35 [1.10, 1.66]; p = 0.004; I² = 0%). On subgroup analysis, it was seen that results from retrospective studies showed higher short-term mortality in the MVI group in comparison with prospective studies (p = 0.003). The certainty in estimates is low due to the largely observational nature of the evidence. In conclusion, MVI provides no additional reduction in short- or long-term mortality in AMI patients with multivessel disease and CS. Additionally, the risk of renal failure may be higher with the use of MVI.

Culprit Vessel Only Versus Multivessel Percutaneous Coronary Intervention in Acute Myocardial Infarction with Cardiogenic Shock: A Systematic Review and Meta-Analysis

BACKGROUND

Previous studies comparing outcomes between culprit vessel only percutaneous coronary intervention (CV-PCI) versus multivessel percutaneous coronary intervention (MV-PCI) in patients with cardiogenic shock in the setting of acute myocardial infarction have shown conflicting results. This meta-analysis investigates the optimal approach for management of these patients considering recently published data.

METHODS

Electronic databases including MEDLINE, ClinicalTrials.gov and the Cochrane Library were searched for all clinical studies published until May 1, 2018, which compared outcomes in patients presenting with acute myocardial infarction and cardiogenic shock. Studies comparing CV-PCI versus MV-PCI in patients with multivessel coronary artery disease were screened for inclusion in final analysis. The primary end point was in-hospital/30 day mortality. Secondary endpoints included long term (>6 months) mortality, renal failure requiring renal replacement therapy, stroke, bleeding, and recurrent myocardial infarction. Odds ratio (OR) with 95% of confidence interval (CI) were computed and p values <0.05 were considered significant.

RESULTS

Patient who underwent CV-PCI had significantly lower short-term mortality (in-hospital or 30-day mortality) (OR: 0.73, CI: 0.61-0.87, p = 0.0005), and lower odds of severe renal failure requiring renal replacement therapy (OR: 0.76, CI: 0.59-0.98, p = 0.03). There was no statistically significant difference in long-term mortality, stroke, bleeding, and recurrent myocardial infarction between two groups.

CONCLUSION

This meta-analysis showed lower short-term mortality and decreased odds of renal failure requiring renal replacement therapy with CV-PCI compared to MV-PCI. However, subgroup analysis including studies exclusively assessing STEMI patients revealed no statistically significant difference in outcomes. Further randomized trials are needed to confirm these findings and evaluate long term results.

Meta-Analysis Comparing Complete or Culprit Only Revascularization in Patients With Multivessel Disease Presenting With Cardiogenic Shock

The optimal strategy for patients with an acute myocardial infarction (MI) and multivessel (MV) coronary artery disease complicated by cardiogenic shock (CS) remains unknown. We conducted a meta-analysis of all randomized controlled trials and observational studies that reported adjusted effect measures to evaluate the association of MV-PCI (percutaneous coronary intervention), compared with culprit only (C)-PCI, with cardiovascular events in patients admitted for CS and MV disease. We identified 12 studies (n = 1 randomized controlled trials, n = 11 observational) that included 7,417 patients (n = 1,809 treated with MV-PCI and n = 5,608 with C-PCI). When compared with C-PCI, MV-PCI was not associated with an increased risk of short-term death (odds ratio [OR] 1.14, 95% confidence interval [CI] 0.87 to 1.48, p = 0.35 and adjusted OR [OR_adj] 1.00, 95% CI 0.70 to 1.43, p = 1.00). In-hospital and/or short-term mortality tended to be higher with MV-PCI, when compared with C-PCI, for CS patients needing dialysis (ß 0.12, 95% CI from 0.049 to 0.198; p= 0.001), whereas MV-PCI was associated with lower in-hospital and/or short-term mortality in patients with an anterior MI (ß -0.022, 95% CI -0.03 to -0.01; p <0.001). MV-PCI strategy was associated with a more frequent need for dialysis or contrast-induced nephropathy after revascularization (OR 1.36, 95% CI 1.06 to 1.75, p = 0.02). In conclusion, MV-PCI seems not to increase risk of death during short- or long-term follow-up when compared with C-PCI in patients admitted for MV coronary artery disease and MI complicated by CS. Furthermore, it appears a more favorable strategy in patients with anterior MI, whereas the increased risk for AKI and its negative prognostic impact should be considered in decision-making process. Further studies are needed to confirm our hypothesis on in these subpopulations of CS patients.

Predictors of Outcomes in Myocardial Infarction and Cardiogenic Shock

Myocardial infarction (MI) complicated by cardiogenic shock (MI-CS) is a major cause of cardiovascular morbidity and mortality. Predictors of outcomes in MI-CS include clinical, laboratory, radiologic variables, and management strategies. This article reviews the existing literature on short- and long-term predictors and risk stratification in MI complicated by CS.

Results of a 10-Year Experience in Korea Using Drug-Eluting Stents During Percutaneous Coronary Intervention for Acute Myocardial Infarction (from the Korea Acute Myocardial Infarction Registry)

Limited information exists about characteristics of patients with acute myocardial infarction (AMI) in Asia. We examined trends in interventional treatment and clinical outcomes for AMI from the Korea Acute Myocardial Infarction Registry (KAMIR). The study population was derived from patients in the KAMIR from November 2005 to December 2016. We identified 54,402 patients with ST-elevation myocardial infarction (STEMI) (n = 29,222) and non-ST-elevation myocardial infarction (NSTEMI) (n = 25,180). The rate of percutaneous coronary intervention (PCI) increased to 96.2% of STEMI group and 84.3% of NSTEMI group in 2016, respectively (All p_trend <0.001). Furthermore, the rate of successful PCI was 97.3% in STEMI and 97.9% in NSTEMI. The rate of primary PCI increased from 67.8% in 2005 to 96.9% in 2016 (p_trend <0.001). Moreover, in patients with STEMI, the proportion of drug-eluting stent implantation increased from 88.8% in 2005 to 97.9% in 2016 (p_trend <0.001). Regarding 1-year clinical outcomes, incidence of definite stent thrombosis was 0.5%, 0.6%, and 0.4% in patients with AMI, STEMI, and NSTEMI, respectively. Moreover, 1-year mortality of AMI improved almost 40% compared with in 2005 (11.4% in 2005 and 6.7% in 2015, p_trend <0.001). In Korean patients with AMI, the rate of primary PCI and drug-eluting stent implantation in STEMI was evidently higher than in the Western registries. In 1-year clinical outcomes, the incidence of stent thrombosis was low and mortality of AMI gradually improved and was lower than in the Western registries.

Revascularization strategies in cardiogenic shock complicating acute myocardial infarction: A systematic review and meta-analysis

BACKGROUND

The optimal revascularization strategy in patients with multi-vessel disease (MVD) presenting with acute myocardial infarction (AMI) and cardiogenic shock (CS) remains unclear.

OBJECTIVE

To investigate the comparative differences between culprit-only revascularization (COR) versus instant multi-vessel revascularization (IMVR) in AMI and CS.

METHODS

13 studies were selected using MEDLINE, EMBASE and the CENTRAL (Inception - 31 November2017). Outcomes were assessed at short-term (in-hospital or ≤30 days duration) and long-term duration (≥6 months). Estimates were reported as random effects relative risk (RR) with 95% confidence interval (CI).

RESULTS

In analysis of 7311 patients, COR significantly reduced the relative risk of short-term all-cause mortality (RR: 0.87; 95% CI, 0.77-0.97; p = 0.01, I² = 50%) and renal failure (RR: 0.75; 95% CI, 0.61-0.94; p = 0.01, I² = 7%) compared with IMVR. There were no significant differences between both the strategies in terms of reinfarction (RR: 1.25; 95% CI, 0.59-2.63; p = 0.56, I² = 0%), major bleeding (RR: 0.88; 95% CI, 0.75-1.04; p = 0.14, I² = 0%) and stroke (RR: 0.77; 95% CI, 0.50-1.17; p = 0.22, I² = 0%) at short term duration. Similarly, no significant differences were observed between both groups regarding all-cause mortality (RR; 1.01; 95% CI, 0.85-1.20; p = 0.93, I² = 61%) and reinfarction (RR: 0.71; 95% CI, 0.34-1.47; p = 0.35, I² = 26%) at long term duration.

CONCLUSION

In MVD patients presenting with AMI and CS, IMVR was comparable to COR in terms of all-cause mortality at long term follow up duration. These results are predominantly derived from observational data and more randomized controlled trials are required to validate this impression.

Complete Versus Culprit-Only Revascularization in STEMI: a Contemporary Review

PURPOSE OF REVIEW

In ST-segment elevation myocardial infarction, urgent revascularization of the culprit coronary vessel and restoration of coronary flow is the goal of the initial management. However, obstructive non-culprit disease is frequently concomitantly found during initial angiography and portends a poor prognosis. Management of non-culprit lesions in ST-segment elevation myocardial infarction (STEMI) has been the subject of extensive debate. This review will examine the currently available evidence, with a specific focus on randomized clinical trials performed to date.

RECENT FINDINGS

Although early observational data suggested better outcomes with culprit-only revascularization, more recent data from several randomized trials have suggested improved outcomes with complete multivessel revascularization, either during the index PCI procedure or as a staged procedure. Data from recent randomized controlled trials have suggested the superiority of complete or multivessel revascularization and have subsequently led to changes to the most recent iterations of STEMI guidelines. However, the optimal management and timing of revascularization of non-culprit lesions in STEMI remain controversial.

Cardiogenic Shock: Recent Developments and Significant Knowledge Gaps

PURPOSE OF REVIEW

Patients with cardiogenic shock (CS) continue to have high rates of morbidity and mortality. We aimed to describe current principles in the management of CS including coronary revascularization, medical management, mechanical circulatory support, and supportive care.

RECENT FINDINGS

Revascularization is still recommended, but trials have not found a benefit in the revascularization of nonculprit artery lesions. New mechanical circulatory support options are available, but optimal use remains uncertain. Overall improvement in outcomes appears to have plateaued. There remain substantial knowledge gaps about the management of CS. The ideal timing and selection criteria for mechanical support remain under-developed. There has been little systematic study to inform medical management or supportive care of this patient population. A more expansive research focus is necessary to improve the care of CS.

Culprit Vessel-Only Versus Multivessel Percutaneous Coronary Intervention in Patients With Cardiogenic Shock Complicating ST-Segment-Elevation Myocardial Infarction: A Collaborative Meta-Analysis

BACKGROUND

The optimal revascularization strategy in patients with multivessel disease presenting with cardiogenic shock complicating ST-segment-elevation myocardial infarction remains unknown.

METHODS AND RESULTS

Databases were searched from 1999 to October 2016. Studies comparing immediate/single-stage multivessel percutaneous coronary intervention (MV-PCI) versus culprit vessel-only PCI (CO-PCI) in patients with multivessel disease, ST-segment-elevation myocardial infarction, and cardiogenic shock were included. Primary end point was short-term (in-hospital or 30 days) mortality. Secondary end points included long-term mortality, cardiovascular death, reinfarction, and repeat revascularization. Safety end points were in-hospital stroke, renal failure, and major bleeding. The meta-analysis included 11 nonrandomized studies and 5850 patients (1157 MV-PCI and 4693 CO-PCI). There was no significant difference in short-term mortality with MV-PCI versus CO-PCI (odds ratio [OR], 1.08; 95% confidence interval [CI], 0.81-1.43; P=0.61). Similarly, there were no significant differences in long-term mortality (OR, 0.84; 95% CI, 0.54-1.30; P=0.43), cardiovascular death (OR, 0.72; 95% CI, 0.42-1.23; P=0.23), reinfarction (OR, 1.65; 95% CI, 0.84-3.26; P=0.15), or repeat revascularization (OR, 1.13; 95% CI, 0.76-1.69; P=0.54) between the 2 groups. There was a nonsignificant trend toward higher in-hospital stroke (OR, 1.64; 95% CI, 0.98-2.72; P=0.06) and renal failure (OR, 1.30; 95% CI, 0.98-1.72; P=0.06), with no difference in major bleeding (OR, 1.47; 95% CI, 0.39-5.63; P=0.57) with MV-PCI when compared with CO-PCI.

CONCLUSIONS

This meta-analysis of nonrandomized studies suggests that in patients with cardiogenic shock complicating ST-segment-elevation myocardial infarction, there may be no significant benefit with single-stage MV-PCI compared with CO-PCI. Given the limitations of observational data, randomized trials are needed to determine the role of MV-PCI in this setting.

Interventional therapies in acute myocardial infarction complicated by cardiogenic shock

Cardiogenic shock remains the most common cause of death in patients with acute myocardial infarction. Early revascularization of the infarct-related artery has been shown to reduce mortality and is the therapeutic cornerstone. The optimal revascularization strategy of additional non-culprit lesions remains yet to be determined. Further, uncertainties exist with respect to access site choice, antiplatelet regimen as well as mechanical support devices. This review outlines current evidence on the interventional management of cardiogenic shock complicating acute myocardial infarction.

Contemporary Management of Cardiogenic Shock: A Scientific Statement From the American Heart Association

Cardiogenic shock is a high-acuity, potentially complex, and hemodynamically diverse state of end-organ hypoperfusion that is frequently associated with multisystem organ failure. Despite improving survival in recent years, patient morbidity and mortality remain high, and there are few evidence-based therapeutic interventions known to clearly improve patient outcomes. This scientific statement on cardiogenic shock summarizes the epidemiology, pathophysiology, causes, and outcomes of cardiogenic shock; reviews contemporary best medical, surgical, mechanical circulatory support, and palliative care practices; advocates for the development of regionalized systems of care; and outlines future research priorities.

Multivessel versus culprit lesion only percutaneous coronary intervention in cardiogenic shock complicating acute myocardial infarction: A systematic review and meta-analysis

Background:

Early revascularisation of the culprit lesion is the therapeutic cornerstone in cardiogenic shock complicating acute myocardial infarction. The optimal management of additional non-culprit lesions is unclear. This systematic review and meta-analysis aims to summarise current evidence on the comparison of immediate multivessel percutaneous coronary intervention (MV-PCI) or culprit lesion only PCI with possible staged revascularisation (C-PCI) in patients with cardiogenic shock complicating acute myocardial infarction.

Methods:

Medical literature databases were screened to identify analyses comparing MV-PCI with C-PCI in patients with cardiogenic shock complicating acute myocardial infarction and multivessel coronary artery disease. In absence of randomised trials, 10 cohort studies were included in the current meta-analysis. The primary outcome of short-term mortality was assessed at hospital discharge or 30 days after hospital admission. Secondary outcomes were long-term mortality as well as myocardial re-infarction, stroke, acute renal failure, and bleeding at short-term follow-up.

Results:

Of 6051 patients, 1194 (19.7%) received MV-PCI and 4857 (80.3%) C-PCI. Short-term mortality was 37.5% in patients undergoing MV-PCI compared with 28.8% in C-PCI patients (risk ratio 1.26, 95% confidence interval 1.12–1.41, p=0.001). Long-term mortality ( p=0.77), myocardial re-infarction ( p=0.77), stroke ( p=0.12), acute renal failure ( p=0.17) and bleeding ( p=0.53) did not differ significantly between the two revascularisation groups.

Conclusions:

Results of this first meta-analysis on the interventional management of patients with cardiogenic shock complicating acute myocardial infarction and multivessel coronary artery disease do not support MV-PCI over C-PCI. However, possible treatment selection bias in the individual studies must be taken into account.

Multivessel Revascularization in Shock and High-Risk Percutaneous Coronary Intervention

This review explores the usefulness of multivessel revascularization with percutaneous coronary intervention in patients with multivessel obstructive coronary artery disease (CAD) presenting with and without cardiogenic shock. We also evaluate the literature regarding complete versus incomplete revascularization for patients with cardiogenic shock, acute coronary syndromes, and stable coronary artery disease.

Management of Multivessel Disease and Cardiogenic Shock

Cardiogenic shock represents a state of low cardiac output and systemic hypoperfusion resulting in insufficient end-organ perfusion and consequent multiorgan failure. The main cause of this complication in the context of acute ST-elevation myocardial infarction is left ventricular dysfunction secondary to poor myocardial perfusion. In over 50% of cardiogenic shock cases, there is evidence of significant coronary stenosis within noninfarct-related arteries. Persistent ischemia in the noninfarct territory may contribute to ongoing hypotension. Currently, ESC and ACC/AHA/SCAI guidelines advocate complete revascularization in the context of multivessel coronary artery disease in the context of cardiogenic shock, although the evidence is weak.

Controversies and Challenges in the Management of ST-Elevation Myocardial Infarction Complicated by Cardiogenic Shock

The prognosis in ST-elevation myocardial infarction has improved with coronary care units, revascularization, and anticoagulant strategies; however, cardiogenic shock (CS) remains a highly fatal condition. Controversies remain about optimal pharmacologic therapies, revascularization strategies, the role of mechanical circulatory support (MCS), and evidence-based patient selection. The current informed consent paradigm for clinical trials creates challenges testing treatments in CS patients, who are too ill to consent and require immediate treatment. Several trials are underway comparing revascularization strategies and MCS options. Although the prognosis is grim, careful, new and existing treatments could change the course of this condition in the coming years.

Meta-Analysis of the Optimal Percutaneous Revascularization Strategy in Patients With Acute Myocardial Infarction, Cardiogenic Shock, and Multivessel Coronary Artery Disease

The optimal percutaneous coronary intervention (PCI) revascularization strategy in patients with multivessel (MV) coronary artery disease (CAD) who present with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) has not been systematically addressed. Accordingly, we performed a study-level meta-analysis comparing 2 PCI strategies in these patients-infarct-related artery (IRA) only versus MV revascularization. Studies including patients with AMI and MV CAD complicated with CS who received primary PCI were searched from 2000 to 2016. The primary end points were in-hospital/30-day and mid- to long-term (≥6 month) mortality. Fixed and random effects models were used for analysis. Ten studies (9 prospective and 1 retrospective) involving 6,068 patients met our inclusion criteria. IRA-only PCI was the most frequently used revascularization strategy (4,872 patients, 80%), while MV PCI was performed in 1,196 patients (20%). The MV PCI strategy was associated with higher short-term mortality compared with the IRA-only PCI strategy (odds ratio 1.41, 95% confidence interval 1.15 to 1.71, p = 0.008). There was no difference in mid- to long-term mortality between MV PCI and IRA-only strategies (odds ratio 1.02, 95% confidence interval 0.65 to 1.58, p = 0.94). In conclusion, in patients with AMI and MV CAD complicated by CS, the IRA-only PCI strategy seems to be associated with lower short-term, but not mid- to long-term mortality compared with MV PCI. This finding is different from the revascularization strategy recommended by current professional guidelines and suggests the need for dedicated randomized clinical trials.

Prognostic Analysis for Cardiogenic Shock in Patients with Acute Myocardial Infarction Receiving Percutaneous Coronary Intervention

Cardiogenic shock (CS) is uncommon in patients suffering from acute myocardial infarction (AMI). Long-term outcome and adverse predictors for outcomes in AMI patients with CS receiving percutaneous coronary interventions (PCI) are unclear. A total of 482 AMI patients who received PCI were collected, including 53 CS and 429 non-CS. Predictors for AMI patients with CS including recurrent MI, cardiovascular (CV) mortality, all-cause mortality, and repeated-PCI were analyzed. The CS group had a lower central systolic pressure and central diastolic pressure (both P < 0.001). AMI patients with hypertension history were less prone to develop CS (P < 0.001). Calcium channel blockers and statins were less frequently used by the CS group than the non-CS group (both P < 0.05) after discharge. Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score, CV mortality, and all-cause mortality were higher in the CS group than the non-CS group (all P < 0.005). For patients with CS, stroke history was a predictor of recurrent MI (P = 0.036). CS, age, SYNTAX score, and diabetes were predictors of CV mortality (all P < 0.05). CS, age, SYNTAX score, and stroke history were predictors for all-cause mortality (all P < 0.05). CS, age, and current smoking were predictors for repeated-PCI (all P < 0.05).

Managing Multivessel Coronary Artery Disease in Patients With ST-Elevation Myocardial Infarction: A Comprehensive Review

Multivessel coronary artery disease (CAD) is found in up to 60% of the patients presenting with an ST-elevation myocardial infarction (STEMI) and worsens the prognosis proportional to the extent of CAD severity. However, the 2013 American College of Cardiology/American Heart Association STEMI guidelines, based on mostly observational data, had recommended against a routine noninfarct-related artery percutaneous coronary intervention (PCI). After these guidelines were published, a handful of randomized trials became available, and they suggested that PCI of significant lesions in a noninfarct-related artery at the time of primary PCI might result in improved patient outcomes. The incidence of major adverse cardiac events was significantly reduced by 55% at 1 year and 65% at 2 years in patients undergoing angiographically guided PCI of nonculprit vessels at the time of primary PCI, in 2 different randomized trials. Fractional flow reserve-guided PCI of nonculprit vessels in this setting has also been shown to reduce cardiac events by 44% at 1 year. Meta-analyses of both nonrandomized and randomized trials have also suggested that complete revascularization at the time of STEMI significantly improves outcomes, including long-term all-cause mortality. In view of the emerging data, a focused update on primary PCI was published in 2015 and suggested that PCI of noninfarct-related arteries might be considered in selected patients. This article is a comprehensive review of the literature on the treatment of multivessel CAD in patients with STEMI, which provides the reader a critical analysis of the available information to determine the best therapeutic approach.

Cardiogenic Shock Predicts Long-term Mortality in Hospital Survivors of STEMI Treated With Primary Percutaneous Coronary Intervention

BACKGROUND

ST-segment elevation myocardial infarction (STEMI) complicated by cardiogenic shock (CS) has a poor prognosis. Recently published data suggested, however, that CS does not affect long-term mortality in hospital survivors of STEMI. We investigated whether this could be confirmed in a larger cohort.

HYPOTHESIS

STEMI complicated by CS leads to worse long-term survival.

METHODS

A prospective cohort study was performed in 7412 consecutive patients with STEMI treated by primary percutaneous coronary intervention (angioplasty). The predictive value of CS on long-term mortality was assessed in hospital survivors. Multivariate analysis, adjusting for differences in baseline variables, was performed to assess the independent prognostic value of CS.

RESULTS

Cardiogenic shock was observed in 387 patients (5.2%). The total in-hospital mortality was 254 (3.4%), and mortality was significantly higher in patients with CS (20.0% vs 2.6%; P < 0.001). The 1-year mortality in hospital survivors was 10.3% in patients with CS and 3.9% in patients without CS (P < 0.001). After multivariate analysis, CS was still a significant predictor of long-term mortality in hospital survivors (hazard ratio: 2.6, 95% confidence interval: 1.64-4.01).

CONCLUSIONS

Cardiogenic shock remains a strong predictor of long-term mortality in hospital survivors of STEMI treated by primary percutaneous coronary intervention.

[Immediate multivessel PCI in patients with ACS : Is less more?]

Approximately 50 % of hemodynamically stable patients with ST-segment elevation myocardial infarction (STEMI) and up to 80 % of patients with infarction-related cardiogenic shock have multivessel coronary artery disease. The optimal revascularization strategy in these patients has still not been defined. Following successful percutaneous coronary intervention (PCI) of the culprit lesion, immediate PCI of all additional lesions or staged PCI, after invasive or non-invasive proof of ischemia or conservative therapy can be considered. Randomized studies have demonstrated a clinical benefit of immediate or staged multivessel PCI compared to a conservative approach. So far there are no randomized studies available comparing immediate versus staged PCI. The data regarding the optimal strategy in patients with cardiogenic shock show low concordance. The currently running CULPRIT shock study will help to define the optimal strategy in shock patients. This manuscript summarizes the current knowledge and data and provides recommendations for the clinical practice.

Predictors of Mortality in Patients with ST-Segment Elevation Acute Myocardial Infarction and Resuscitated Out-of-Hospital Cardiac Arrest

Introduction

In patients with out-of-hospital cardiac arrest (OHCA) complicating an ST-segment elevation myocardial infarction (STEMI), the survival depends largely on the restoration of coronary flow in the infarct related artery. The aim of this study was to determine clinical and angiographic predictors of in-hospital mortality in patients with OHCA and STEMI, successfully resuscitated and undergoing primary percutaneous intervention (PCI).

Methods

From January 2013 to July 2015, 78 patients with STEMI presenting OHCA, successfully resuscitated, transferred immediately to the catheterization unit and treated with primary PCI, were analyzed. Clinical, laboratory and angiographic data were compared in 28 non-survivors and 50 survivors.

Results

The clinical baseline characteristics of the study population showed no significant differences between the survivors and non-survivors in respect to age (p=0.06), gender (p=0.8), the presence of hypertension (p=0.4), dyslipidemia (p=0.09) obesity (p=1), smoking status (p=0.2), presence of diabetes (p=0.2), a clinical history of acute myocardial infarction (p=0.7) or stroke (p=0.17). Compared to survivors, the non-survivor group exhibited a significantly higher incidence of cardiogenic shock (50% vs 24%, p=0.02), renal failure (64.3% vs 30.0%, p=0.004) and anaemia (35.7% vs 12.0%, p=0.02). Three-vessel disease was significantly higher in the non-survivor group (42.8% vs. 20.0%, p=0.03), while there was a significantly higher percentage of TIMI 3 flow postPCI in the infarct-related artery in the survivor group (80.% vs. 57.1%, p=0.03). The time from the onset of symptoms to revascularization was significantly higher in patients who died compared to those who survived (387.5 +/- 211.3 minutes vs 300.8 +/- 166.1 minutes, p=0.04), as was the time from the onset of cardiac arrest to revascularization (103.0 +/- 56.34 minutes vs 67.0 +/- 44.4 minutes, p=0.002). Multivariate analysis identified the presence of cardiogenic shock (odds ratio [OR]: 3.17, p=0.02), multivessel disease (OR: 3.0, p=0.03), renal failure (OR: 4.2, p=0.004), anaemia (OR: 4.07, p=0.02), need for mechanical ventilation >48 hours (OR: 8.07, p=0.0002) and a duration of stay in the ICU longer than 5 days (OR: 9.96, p=0.0002) as the most significant independent predictors for mortality in patients with OHCA and STEMI.

Conclusion

In patients surviving an OHCA in the early phase of a myocardial infarction, the presence of cardiogenic shock, renal failure, anaemia or multivessel disease, as well as a longer time from the onset of symptoms or of cardiac arrest to revascularization, are independent predictors of mortality. However, the most powerful predictor of death is the duration of stay in the ICU and the requirement of mechanical ventilation for more than forty-eight hours.

Multivessel versus culprit lesion only percutaneous revascularization plus potential staged revascularization in patients with acute myocardial infarction complicated by cardiogenic shock: Design and rationale of CULPRIT-SHOCK trial

BACKGROUND

In acute myocardial infarction complicated by cardiogenic shock (CS), up to 80% of patients present with multivessel coronary artery disease. Currently, the best revascularization strategy is unknown. Therefore, a prospective randomized adequately powered clinical trial is warranted.

STUDY DESIGN

The CULPRIT-SHOCK study is a 706-patient controlled, international, multicenter, randomized, open-label trial. It is designed to compare culprit lesion only percutaneous coronary intervention (PCI) with possible staged non-culprit lesion revascularization versus immediate multivessel PCI in patients with CS complicating acute myocardial infarction. Patients will be randomized in a 1:1 fashion to one of the two treatment arms. The primary efficacy endpoint of CULPRIT-SHOCK is 30-day mortality and severe renal failure requiring renal replacement therapy. Secondary outcome measures such as hemodynamic, laboratory, and clinical parameters will serve as surrogate endpoints for prognosis. Furthermore, an intermediate- and long-term follow-up at 6 and 12 months will be performed. Safety endpoints include the assessment of bleeding and stroke.

CONCLUSIONS

The CULPRIT-SHOCK trial will address the question of optimal revascularization strategy in patients with multivessel disease and acute myocardial infarction complicated by CS.

Familial hypobetalipoproteinemia: genetics and metabolism

Familial hypobetalipoproteinemia (FHBL), an autosomal dominant disorder, is defined as <5th percentile LDL-cholesterol or apolipoprotein (apo) B in the plasma. FHBL subjects are generally heterozygous and asymptomatic. Three genetic forms exist: (i) premature stop codon specifying mutations of APOB; (ii) FHBL linked to a susceptibility locus on the chromosome 3p21; and (iii) FHBL linked neither to APOB nor to the chromosome 3p21. In heterozygous apoB-defective FHBL, the hepatic VLDL export system is defective because apoB 100, the product of the normal allele, is produced at approximately 25% of normal rate, and truncated apoB is cleared too rapidly. The reduced capacity for hepatic triglyceride export increases hepatic fat three-fold. Indexes of adiposity and insulin action are similar to controls. 'Knock-in' mouse models of apoB truncations resemble human FHBL phenotypes. Liver fat in the chromosome 3p21-linked FHBL is normal. Elucidation of the genetic basis of the non-apoB FHBL could uncover attractive targets for lipid-lowering therapy. (See note added in proof.).