Intravascular lithotripsy for severe coronary calcification: a systematic review

INTRODUCTION

Coronary artery calcification remains a challenge in percutaneous coronary interventions, due to the higher risk of suboptimal result with subsequent poor clinical outcomes. Intravascular lithotripsy is a novel way of treating severe coronary calcification as it has the ability to modify calcium both circumferentially as well as transmurally, facilitating stent expansion and apposition. We conducted a systematic overview of the published literature on intravascular lithotripsy (IVL) assessing the efficacy and feasibility of IVL in treating severe coronary calcification.

EVIDENCE ACQUISITION

Of the retrieved publications, 62 met our inclusion criteria and were included. A total of 1389 patients (1414 lesions) with significant coronary calcification or under-expanded stents underwent IVL.

EVIDENCE SYNTHESIS

The mean age was 72.03 years (74.7% male). There was a significant improvement in acute and sustained vessel patency, with mean minimal lumen diameter of 2.78±0.46 mm, resulting in acute gain of 1.72±0.51 mm. The acute procedural success rate was 78.2 to 100% with in-hospital complication rate of 5.6 to 7.0%. The majority of the studies reported 30-day MACE, which was between 2.2 to 7.8%.

CONCLUSIONS

The recent studies have highlighted that the use of IVL with adjuvant intracoronary imaging has revolutionized the way of treating heavily calcified, non-dilatable coronary lesions and is likely to succeed the conventional ways of treating these complex lesions. We need further studies to gauge the long-term efficacy and safety of IVL against techniques currently available for calcium modification including conventional balloons, cutting or scoring balloons, rotational atherectomy and laser atherectomy.

Amplified inhibition of atherosclerotic plaque-induced platelet activation by glenzocimab with dual antiplatelet therapy

BACKGROUND

Aspirin and platelet P2Y12 inhibitors, such as ticagrelor, suboptimally inhibit microvascular thrombosis during ST-elevation myocardial infarction. Glycoprotein (GP) IIb/IIIa inhibitors may further inhibit this but cause excessive bleeding.

OBJECTIVES

We investigated whether combination of glenzocimab, a GPVI inhibitor, with aspirin and ticagrelor provides additional antithrombotic effects, as GPVI has a critical role in atherothrombosis but minimal involvement in hemostasis.

METHODS

We investigated the effects of glenzocimab (monoclonal antibody Fab fragment) using blood from healthy donors and patients with acute coronary syndrome treated with aspirin and ticagrelor. Platelets were stimulated with multiple agonists, including atherosclerotic plaque, from patients undergoing carotid endarterectomy.

RESULTS

Aspirin and ticagrelor partially inhibited atherosclerotic plaque-induced platelet aggregation by 48% compared with control (34 ± 3 vs 65 ± 4 U; P < .001). Plaque-induced platelet aggregation, adhesion, secretion, and activation were critically dependent on GPVI activation. Glenzocimab alone reduced plaque-induced aggregation by 75% compared with control (16 ± 4 vs 65 ± 4 U; P < .001) and by >95% when combined with aspirin and ticagrelor (3 ± 1 vs 65 ± 4 U; P < .001). Glenzocimab reduced platelet aggregation, adhesion, and thrombin generation when added to blood of aspirin- and ticagrelor-treated patients with acute coronary syndrome. Glenzocimab shared several antithrombotic effects with the GPIIb/IIIa inhibitor eptifibatide with less effect on general hemostasis assessed by rotational thromboelastometry. In a murine intravital model of ST-elevation myocardial infarction, genetic depletion of GPVI reduced microvascular thrombosis.

CONCLUSION

Addition of glenzocimab to aspirin and ticagrelor enhances platelet inhibition via multiple mechanisms of atherothrombosis. Compared with a GPIIb/IIIa inhibitor, glenzocimab shares multiple antithrombotic effects, with less inhibition of mechanisms involved in general hemostasis.

Treatment gaps in the implementation of LDL cholesterol control among high- and very high-risk patients in Europe between 2020 and 2021: the multinational observational SANTORINI study

Background

European data pre-2019 suggest statin monotherapy is the most common approach to lipid management for preventing cardiovascular (CV) events, resulting in only one-fifth of high- and very high-risk patients achieving the 2019 ESC/EAS recommended low-density lipoprotein cholesterol (LDL-C) goals. Whether the treatment landscape has evolved, or gaps persist remains of interest.

Methods

Baseline data are presented from SANTORINI, an observational, prospective study that documents the use of lipid-lowering therapies (LLTs) in patients ≥18 years at high or very high CV risk between 2020 and 2021 across primary and secondary care settings in 14 European countries.

Findings

Of 9602 enrolled patients, 9044 with complete data were included (mean age: 65.3 ± 10.9 years; 72.6% male). Physicians reported using 2019 ESC/EAS guidelines as a basis for CV risk classification in 52.0% (4706/9044) of patients (overall: high risk 29.2%; very high risk 70.8%). However, centrally re-assessed CV risk based on 2019 ESC/EAS guidelines suggested 6.5% (308/4706) and 91.0% (4284/4706) were high- and very high-risk patients, respectively. Overall, 21.8% of patients had no documented LLTs, 54.2% were receiving monotherapy and 24.0% combination LLT. Median (interquartile range [IQR]) LDL-C was 2.1 (1.6, 3.0) mmol/L (82 [60, 117] mg/dL), with 20.1% of patients achieving risk-based LDL-C goals as per the 2019 ESC/EAS guidelines.

Interpretation

At the time of study enrolment, 80% of high- and very high-risk patients failed to achieve 2019 ESC/EAS guidelines LDL-C goals. Contributory factors may include CV risk underestimation and underutilization of combination therapies. Further efforts are needed to achieve current guideline-recommended LDL-C goals.

Trial registration

ClinicalTrials.gov Identifier: NCT04271280.

Funding

This study is funded by Daiichi Sankyo Europe GmbH, Munich, Germany.

Smartphone and wearable detected atrial arrhythmias in Older Adults: Results of a fully digital European Case finding study

Aims

Simplified detection of atrial arrhythmias via consumer-electronics would enable earlier therapy in at-risk populations. Whether this is feasible and effective in older populations is not known.

Methods and results

The fully remote, investigator-initiated Smartphone and wearable detected atrial arrhythmia in Older Adults Case finding study (Smart in OAC-AFNET 9) digitally enrolled participants ≥65 years without known atrial fibrillation, not receiving oral anticoagulation in Germany, Poland, and Spain for 8 weeks. Participants were invited by media communications and direct contacts. Study procedures adhered to European data protection. Consenting participants received a wristband with a photoplethysmography sensor to be coupled to their smartphone. The primary outcome was the detection of atrial arrhythmias lasting 6 min or longer in the first 4 weeks of monitoring. Eight hundred and eighty-two older persons (age 71 ± 5 years, range 65-90, 500 (57%) women, 414 (47%) hypertension, and 97 (11%) diabetes) recorded signals. Most participants (72%) responded to adverts or word of mouth, leaflets (11%) or general practitioners (9%). Participation was completely remote in 469/882 persons (53%). During the first 4 weeks, participants transmitted PPG signals for 533/696 h (77% of the maximum possible time). Atrial arrhythmias were detected in 44 participants (5%) within 28 days, and in 53 (6%) within 8 weeks. Detection was highest in the first monitoring week [incidence rates: 1st week: 3.4% (95% confidence interval 2.4-4.9); 2nd-4th week: 0.55% (0.33-0.93)].

Conclusion

Remote, digitally supported consumer-electronics-based screening is feasible in older European adults and identifies atrial arrhythmias in 5% of participants within 4 weeks of monitoring (NCT04579159).

Interactions Between Atrial Fibrillation and Natriuretic Peptide in Predicting Heart Failure Hospitalization or Cardiovascular Death

Background Natriuretic peptides are routinely quantified to diagnose heart failure (HF). Their concentrations are also elevated in atrial fibrillation (AF). To clarify their value in predicting future cardiovascular events, we measured natriuretic peptides in unselected patients with cardiovascular conditions and related their concentrations to AF and HF status and outcomes. Methods and Results Consecutive patients with cardiovascular conditions presenting to a large teaching hospital underwent clinical assessment, 7-day ECG monitoring, and echocardiography to diagnose AF and HF. NT-proBNP (N-terminal pro-B-type natriuretic peptide) was centrally quantified. Based on a literature review, four NT-proBNP groups were defined (<300, 300-999, 1000-1999, and ≥2000 pg/mL). Clinical characteristics and NT-proBNP concentrations were related to HF hospitalization or cardiovascular death. Follow-up data were available in 1616 of 1621 patients (99.7%) and analysis performed at 2.5 years (median age, 70 [interquartile range, 60-78] years; 40% women). HF hospitalization or cardiovascular death increased from 36 of 488 (3.2/100 person-years) in patients with neither AF nor HF, to 55 of 354 (7.1/100 person-years) in patients with AF only, 92 of 369 (12.1/100 person-years) in patients with HF only, and 128 of 405 (17.7/100 person-years) in patients with AF plus HF (P<0.001). Higher NT-proBNP concentrations predicted the outcome in patients with AF only (C-statistic, 0.82; 95% CI, 0.77-0.86; P <0.001) and in other phenotype groups (C-statistic in AF plus HF, 0.66; [95% CI, 0.61-0.70]; P <0.001). Conclusions Elevated NT-proBNP concentrations predict future HF events in patients with AF irrespective of the presence of HF, encouraging routine quantification of NT-proBNP in the assessment of patients with AF.

GPVI inhibition by glenzocimab synergistically inhibits atherosclerotic plaque-induced platelet activation when combined with conventional dual antiplatelet therapy

Introduction

Aspirin and a potent platelet P2Y12 inhibitor, such as prasugrel or ticagrelor, are not always sufficient to prevent thrombus formation in patients with ST-elevation MI (STEMI), leading to “slow flow” or “no reflow” effects after stenting. GPIIb/IIIa inhibitors, such as eptifibatide, may help in this setting, but are not used routinely due to their bleeding risk. GPVI has critical roles in thrombosis and a minimal role in haemostasis. Here we tested whether depletion of GPVI has effects on thrombus formation after MI in an animal model and investigated the effects of a novel platelet GPVI inhibitor, glenzocimab (a Fab fragment of a monoclonal antibody), on platelet activation and thrombus formation when combined with aspirin and ticagrelor.

Methods

We used intravital microscopy in a murine model of ST-elevation myocardial infarction and ischaemia-reperfusion injury to investigate microvascular thrombosis. We investigated the antithrombotic effects of adding glenzocimab (previously known as ACT017) to blood from healthy donors and 20 patients with ACS treated with aspirin and ticagrelor. We compared the effect of glenzocimab with the GPIIb/IIIa inhibitor eptifibatide ex-vivo. We stimulated platelets with collagen and atherosclerotic plaque material that was sourced from patients undergoing carotid endarterectomy. We investigated effects on platelet aggregation, spreading, signalling, adhesion, thrombin generation, thrombus formation and clot stability ex vivo.

Results

Genetic depletion of GPVI in an animal model of myocardial infarction reduced microvascular thrombosis. Ex vivo, aspirin and ticagrelor partially inhibited atherosclerotic plaque-induced platelet aggregation (assessed by multiple electrode aggregometry) by 48% compared to control (34±3 vs. 65±4 U; P&lt;0.001; Figure 1). Atherosclerotic plaque-induced platelet aggregation, adhesion, secretion and activation were critically dependent on platelet GPVI activation and were potently inhibited by glenzocimab. Glenzocimab alone reduced atherosclerotic plaque-induced platelet aggregation by 75% compared to control (16±4 vs. 65±4 U; P&lt;0.001; Figure 1) and by over 95% when combined with aspirin and ticagrelor (3±1 vs 65±4 U; P&lt;0.001; Figure 1). Furthermore, glenzocimab provided multiple synergistic antithrombotic effects when added to the blood of aspirin and ticagrelor-treated patients with ACS ex vivo. Glenzocimab and the GPIIb/IIIa inhibitor, eptifibatide, had many similar antithrombotic effects but glenzocimab had less effect on mechanisms of general haemostasis compared to eptifibatide, as assessed by ROTEM (Figure 2).

Conclusions

The addition of glenzocimab to aspirin and ticagrelor provides synergistic inhibition of multiple critical mechanisms of atherothrombosis. Glenzocimab and the GPIIb/IIIa inhibitor, eptifibatide, share many similar antithrombotic effects, although glenzocimab has less impact on mechanisms involved in haemostasis compared to eptifibatide.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Academy of Medical Sciences UK Clinical Lecturer Starter GrantRoyal Embassy of Saudi Arabia

The additive prognostic value of coronary calcium score (CCS) to single photon emission computed tomography myocardial perfusion imaging (SPECT-MPI)-real world data from a single center

AIMS

Single-photon emission computed tomography myocardial perfusion imaging [SPECT-MPI] is a functional test for coronary ischemia. We aimed to assess the additive prognostic value of coronary calcium score (CCS) to SPECT-MPI in stable patients.

METHODS

This study is a retrospective analysis of 655 patients who underwent SPECT-MPI with CCS (2012 to 2017). Receiver operator characteristic (ROC) identified CCS cutoff value for all-cause mortality: CCS+ if > cutoff value and MPI+ if ≥ 5% total perfusion defect (TPD). Patients were divided into 1 MPI-/CCS-; 2 MPI+/CCS-; 3 MPI-/CCS+; 4 MPI+/CCS+ and compared. Cox proportional hazard analysis identified predictors of mortality.

RESULTS

CCS cutoff for all-cause mortality was > 216 (C statistic 0.756, P < 0.0001). In MPI+ groups, mean TPD was similar (13.4% and 13.1% respectively) but mortality was higher in the CCS+ (12.5% vs. 4.8%, P = 0.22) as was the severe LV systolic dysfunction (8.0% vs. 0%, P = 0.095). In MPI- groups, mean TPD was similar (0.7% and 0.9% respectively) but all-cause mortality was higher in the CCS+ (10.7% vs. 1.6%, P < 0.0001) as was severe LVSD (2.9 % vs. 0.3% P = 0.016). Age, smoking, renal impairment ,and CCS > 216 were independent predictors of mortality.

CONCLUSIONS

Patients with raised CCS on SPECT-MPI have increased mortality and poor LV function despite a negative MPI.

Evaluation of contemporary treatment of high- and very high-risk patients for the prevention of cardiovascular events in Europe - Methodology and rationale for the multinational observational SANTORINI study

Background and aims

Clinical practice before 2019 suggests a substantial proportion of high and very high CV risk patients taking lipid-lowering therapy (LLT) would not achieve the new LDL-C goals recommended in the 2019 ESC/EAS guidelines (<70 and < 55 mg/dL, respectively). To what extent practice has changed since the last ESC/EAS guideline update is uncertain, and quantification of remaining implementation gaps may inform health policy.

Methods

The SANTORINI study is a multinational, multicentre, prospective, observational, non-interventional study documenting patient data at baseline (enrolment) and at 12-month follow-up. The study recruited 9606 patients ≥18 years of age with high and very high CV risk (as assigned by the investigators) requiring LLT, with no formal patient or comparator groups. The primary objective is to document, in the real-world setting, the effectiveness of current treatment modalities in managing plasma levels of LDL-C in high- and very high-risk patients requiring LLT. Key secondary effectiveness objectives include documenting the relationship between LLT and levels of other plasma lipids, high-sensitivity C-reactive protein (hsCRP) and overall predicted CV risk over one year. Health economics and patient-relevant parameters will also be assessed.

Conclusions

The SANTORINI study, which commenced after the 2019 ESC/EAS guidelines were published, is ideally placed to provide important contemporary insights into the evolving management of LLT in Europe and highlight factors contributing to the low levels of LDL-C goal achievement among high and very high CV risk patients. It is hoped the findings will help enhance patient management and reduce the burden of ASCVD in Europe.

Use of NOACS in high-risk patients with atrial fibrillation in Saudi Arabia: Perspectives on improving patient care

BACKGROUND

Despite the widespread and increasing use of NOACs in Saudi Arabia, there is a lack of contemporary guidance specific to the region. In particular, guidance on NOAC use in high-risk patients who are more likely to experience bleeding with oral anticoagulant therapy is needed. There is an unmet need for a review of contemporary evidence coupled with expert insights on safe and effective NOAC use in high-risk patients with AF in Saudi Arabia.

RESEARCH DESIGN AND METHODS

This article provides a detailed review of contemporary literature on NOAC use in high-risk patients with AF. Additionally, key gaps in the literature are identified and expert insights are shared to guide effective management of patients and the significance of local data is evaluated with respect to challenges in optimizing the use of NOACs.

CONCLUSIONS

This article provides information that complements and expands on existing reviews and guidelines on NOAC use in patients with AF, with a focus on challenges specific to the Saudi Arabian context with the potential to make a positive contribution to the medical community in Saudi Arabia and in other nations.

Effect of the PCSK9 Inhibitor Evolocumab on Total Cardiovascular Events in Patients With Cardiovascular Disease: A Prespecified Analysis From the FOURIER Trial

Importance

The PCSK9 inhibitor evolocumab reduced low-density lipoprotein cholesterol and first cardiovascular events in the Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk (FOURIER) trial, but patients remain at high risk of recurrent cardiovascular events.

Objective

To evaluate the effect of evolocumab on total cardiovascular events, given the importance of total number of cardiovascular events to patients, clinicians, and health economists.

Design, Setting, and Participants

Secondary analysis of a randomized, double-blind clinical trial. The FOURIER trial compared evolocumab or matching placebo and followed up patients for a median of 2.2 years. The study included 27 564 patients with stable atherosclerotic disease receiving statin therapy. Data were analyzed between May 2017 and February 2019.

Main Outcomes and Measures

The primary end point (PEP) was time to first cardiovascular death, myocardial infarction, stroke, hospitalization for unstable angina, or coronary revascularization; the key secondary end point was time to first cardiovascular death, myocardial infarction, or stroke. In a prespecified analysis, total cardiovascular events were evaluated between treatment arms.

Results

The mean age of patients was 63 years, 69% of patients were taking high-intensity statin therapy, and the median LDL-C at baseline was 92 mg/dL (to convert to millimoles per liter, multiply by 0.0259). There were 2907 first PEP events and 4906 total PEP events during the trial. Evolocumab reduced total PEP events by 18% (incidence rate ratio [RR], 0.82; 95% CI, 0.75-0.90; P < .001) including both first events (hazard ratio, 0.85; 95% CI, 0.79-0.92; P < .001) and subsequent events (RR, 0.74; 95% CI, 0.65-0.85). There were 2192 total primary events in the evolocumab group and 2714 total events in the placebo group. For every 1000 patients treated for 3 years, evolocumab prevented 22 first PEP events and 52 total PEP events. Reductions in total events were driven by fewer total myocardial infarctions (RR, 0.74; 95% CI, 0.65-0.84; P < .001), strokes (RR, 0.77; 95% CI, 0.64-0.93; P = .007), and coronary revascularizations (RR, 0.78; 95% CI, 0.71-0.87; P < .001).

Conclusions and Relevance

The addition of the PCSK9 inhibitor evolocumab to statin therapy improved clinical outcomes, with significant reductions in total PEP events, driven by decreases in myocardial infarction, stroke, and coronary revascularization. More than double the number of events were prevented with evolocumab vs placebo as compared with the analysis of only first events. These data provide further support for the benefit of continuing aggressive lipid-lowering therapy to prevent recurrent cardiovascular events.

Trial Registration

ClinicalTrials.gov identifier: NCT01764633.

Rivaroxaban Plus Aspirin Versus Aspirin Alone in Patients With Prior Percutaneous Coronary Intervention (COMPASS-PCI)

Background:

The COMPASS trial (Cardiovascular Outcomes for People using Anticoagulation Strategies) demonstrated that dual pathway inhibition (DPI) with rivaroxaban 2.5 mg twice daily plus aspirin 100 mg once daily versus aspirin 100 mg once daily reduced the primary major adverse cardiovascular event (MACE) outcome of cardiovascular death, myocardial infarction, or stroke, as well as, mortality, in patients with chronic coronary syndromes or peripheral arterial disease. Whether this remains true in patients with a history of percutaneous coronary intervention (PCI) is unknown.

Methods:

In a prespecified subgroup analysis from COMPASS, we examined the outcomes of patients with a chronic coronary syndrome with or without a previous PCI treated with DPI versus aspirin alone. Among patients with a previous PCI, we studied the effects of treatment according to the timing of the previous PCI.

Results:

Of the 27 395 patients in COMPASS, 16 560 patients with a chronic coronary syndrome were randomly assigned to DPI or aspirin, and, of these, 9862 (59.6%) had previous PCI (mean age 68.2±7.8, female 19.4%, diabetes mellitus 35.7%, previous myocardial infarction 74.8%, multivessel PCI 38.0%). Average time from PCI to randomization was 5.4 years (SD, 4.4) and follow-up was 1.98 (SD, 0.72) years. Regardless of previous PCI, DPI versus aspirin produced consistent reductions in MACE (PCI: 4.0% versus 5.5%; hazard ratio [HR], 0.74 [95% CI, 0.61–0.88]; no PCI: 4.4% versus 5.7%; HR, 0.76 [95% CI, 0.61–0.94], P -interaction=0.85) and mortality (PCI: 2.5% versus 3.5%; HR, 0.73 [95% CI, 0.58–0.92]; no PCI: 4.1% versus 5.0%; HR, 0.80 [95% CI, 0.64–1.00], P -interaction=0.59), but increased major bleeding (PCI: 3.3% versus 2.0%; HR, 1.72 [95% CI, 1.34–2.21]; no PCI: 2.9% versus 1.8%; HR, 1.58 [95% CI, 1.15–2.17], P -interaction=0.68). In those with previous PCI, DPI compared with aspirin produced consistent (robust) reductions in MACE irrespective of time since previous PCI (as early as 1 year and as far as 10 years; P -interaction=0.65), irrespective of having a previous myocardial infarction ( P -interaction=0.64).

Conclusions:

DPI compared with aspirin produced consistent reductions in MACE and mortality but with increased major bleeding with or without previous PCI. Among those with previous PCI 1 year and beyond, the effects on MACE and mortality were consistent irrespective of time since last PCI.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01776424.

Considerations and treatment options for patients with comorbid atrial fibrillation and diabetes mellitus

INTRODUCTION

Atrial fibrillation (AF) and diabetes mellitus (DM) are common worldwide and their incidence is increasing, representing a significant public health and economic burden as well as an increase in individual increased morbidity and mortality risk profiles. Both conditions are closely related, as patients with DM are at increased risk of incident AF, and AF patients with DM are at higher risk of cardiovascular events compared to non-AF patients. Areas covered: This review article aims to provide an overview of the current evidence linking DM and AF, as well as the impact of obesity, weight loss and stroke on these coexisting conditions. Second, the effects of new oral anti hyperglycaemic medications on cardiovascular risk will be considered. Expert opinion: In conclusion, coexisting AF and DM represent a high risk population of patients requiring aggressive risk factor identification and treatment optimisation. The multifactorial interplay between these conditions requires individual assessment of patient risk profiles with the aim of minimising the impact of each modifiable risk factor.

Simultaneous computerised activation of the primary percutaneous coronary intervention pathway reduces out-of-hours door-to-balloon time but not mortality

BACKGROUND

In 2009 activation of out of hours (OOH) primary percutaneous coronary intervention (PPCI) in our institution changed from separate telephone calls to a simultaneous computerised alert. We assessed the impact of this protocol change on door-to-balloon (DTB) time, in hospital and 1 year mortality.

METHODS

Retrospective survey of our Myocardial Ischaemia National Audit Project (MINAP) database. OOH patients were categorized--pre- (Group 1) and post- (Group 2) introduction of the computerised alert protocol.

RESULTS

OOH PPCI was performed for 793 patients (mean age 61, 73.4% male)--295 in Group 1 and 498 in Group 2. Median DTB times were 92 min (interquartile range [IQR] 75-111) for Group 1 and 76 min (IQR 64-97) for Group 2 (p < 0.0001). Forty-eight percent achieved DTB in ≤ 90 min in Group 1 compared to 70% in Group 2 (p < 0.0001). Computerised alert was associated with a shorter DTB time on multivariate analysis (beta coefficient -0.09, p = 0.03 for linear regression and OR 2.8, 95% CI 1.6-5.0, p < 0.0001 for logistic regression). In hospital mortality was 4.1% in Group 1 and 5% in Group 2 (p = 0.60). All-cause mortality at 1 year was 6.1% in Group 1 and 9.9% in Group 2 (p = 0.09).

CONCLUSIONS

Simultaneous computerised activation for OOH PPCI reduced DTB times, increased the number of patients achieving target DTB times but did not affect mortality.

Hibernating myocardium in heart failure

Ischemic left ventricular systolic dysfunction may result from myocardial necrosis or from hypocontractile areas of viable myocardium. In some cases, recovery of contractility may occur on revascularization--this reversibly dysfunctional tissue is commonly referred to as hibernating myocardium. Observational data suggest that revascularization of patients with ischemic left ventricular systolic dysfunction and known viable myocardium provides a survival benefit over medical therapy. Identification of viable, dysfunctional myocardium may be especially worthwhile in deciding which patients with ischemic left ventricular systolic dysfunction will benefit from revascularization procedures. Randomized, prospective trials evaluating this are currently ongoing. This review will provide an overview of the complex pathophysiology of viable, dysfunctional myocardium, and will discuss outcomes after revascularization. Of the techniques used to determine the presence of hibernating myocardium, functional methods such as stress echocardiography and cardiac magnetic resonance appear more specific, but less sensitive, than the nuclear modalities, which assess perfusion and metabolic activity. Currently, the availability of all methods is variable.

Statin prescription is essential in peripheral vascular disease

Hypercholesterolemia is an important and easily modifiable risk factor for peripheral arterial disease (PAD), but is frequently not adequately addressed by vascular interventionists. Patients with PAD often have extensive atherosclerotic disease elsewhere and have a 1-year mortality rate as high as 20%, mainly from cardiovascular events. This case discussion briefly addresses the evidence for treating hypercholesterolemia in this subgroup of patients. Statins not only lower cholesterol, but also are antiinflammatory, antiproliferative, and antithrombogenic, and improve endothelial function. Current guidelines are reviewed and an approach to initiation of statins and their management is discussed.

A 'Reveal'ing Diagnosis

The present case report describes a 54-year-old woman with recurrent syncope of undetermined etiology. Despite several cardiological and neurological investigations, no firm diagnosis was established until an insertable loop recorder (REVEAL Plus Model 9526, Medtronic Inc., Minneapolis, MN, USA) revealed muscle twitch artifact secondary to a seizure disorder.

Aquaporin-1 is expressed by vascular smooth muscle cells and mediates rapid water transport across vascular cell membranes

The aquaporins are a rapidly expanding family of highly conserved proteins which function as transmembrane water channels. We have previously shown that the gene for aquaporin-1 (AQP-1) is expressed in rat, aortic vascular smooth muscle cells (VSMCs) implying a specific role for AQP-1 in vascular function. In this study we set out to document the expression of AQP-1 in human arteries and found mRNA and protein in normal endothelial and VSMCs of human arteries and capillaries and in a subset of VSMCs in human atherosclerotic plaques. Secondly, we examined the regulation of AQP-1 gene expression during vascular development and following vascular injury. Studies in the rat demonstrated that AQP-1 mRNA is induced in the neonatal aorta at week 2 of postnatal development and that the protein is present in neointimal VSMCs following balloon injury. Finally, by measuring the rate of change in cell size induced by changes in external osmolarity and demonstrating that water transport can be inhibited with mercuric chloride, we show that AQP-1 is responsible for water transport across human VSMC membranes. Thus, this study provides evidence for a hitherto unrecognised role for aquaporins in mediating rapid water transport across human VSMC membranes. By analogy with other tissues, these data argue for an important role for AQP-1 in regulating transcellular fluid flow and tissue hydration.

The aquaporins. A family of water channel proteins

The recent discovery of aquaporins, a family of highly conserved water channel proteins, which are expressed in both eukaryotes and prokaryotes, has provoked a re-evaluation of the physiology of water transport in all organisms. So far, seven distinct aquaporins have been characterised in mammals, but highly homologous family members have also been found in amphibians, insects, plants and bacteria. These transmembrane proteins serve to facilitate water transport down osmotic gradients with low activation energy. Alterations in channel expression, cellular targeting and perhaps channel permeability regulate membrane water transport. Naturally occurring and experimentally produced mutations in aquaporins cause a variety of perturbations of water homeostasis. Manipulation of aquaporin expression may have a therapeutic role in several disease processes including cardiac failure and the ascites associated with liver disease.

Identification of right atrial thrombi using transoesophageal echocardiography

The in vivo diagnosis of right atrial thrombus is difficult by transthoracic echocardiography and it is likely that small thrombi are underdiagnosed using this approach. Transoesophageal echocardiography provides an unobstructed view of cardiac structures and the great vessels. In this report we describe the findings in five patients with right atrial thrombi that illustrate the potential usefulness of transoesophageal echocardiography for both the initial diagnosis and the subsequent management of these patients.

Acute coronary embolism complicating aortic valve endocarditis treated with streptokinase and aspirin. A case report

Bacterial endocarditis may present with acute chest pain due to coronary embolization and mimics acute myocardial infarction secondary to coronary atherosclerosis. We present the first case report of coronary embolization secondary to aortic valve endocarditis treated with standard doses of streptokinase and aspirin. The patient survived but sustained a large myocardial infarction and a major gastrointestinal bleed. Infective endocarditis should be considered in all patients presenting with acute chest pain. When myocardial infarction is due to coronary embolism from endocarditic valves standard thrombolysis regimes should be avoided.

Horner's syndrome occurring as a complication of pleurectomy

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