Long-term clinical outcome after fractional flow reserve- versus angio-guided percutaneous coronary intervention in patients with intermediate stenosis of coronary artery bypass grafts

BACKGROUND

Fractional flow reserve (FFR)-guided percutaneous revascularization (percutaneous coronary intervention [PCI]) of intermediate stenosis in native coronary artery is safe and associated with better clinical outcomes as compared with an angiography-guided PCI. It is unknown whether this applies to coronary artery bypass grafts (CABGs).

METHODS

We included 223 patients with CABG and with stable or unstable angina and an intermediate stenosis involving an arterial or a venous graft. Patients were divided into 2 groups: FFR guided (n = 65, PCI performed in case of FFR ≤0.80) and angio guided (n = 158, PCI performed based on angiographic evaluation). Primary end point was major adverse cardiac and cerebrovascular event, defined as death, myocardial infarction, target vessel failure, and cerebrovascular accident (CVA).

RESULTS

The 2 groups were similar in terms of demographic and clinical characteristics. Percutaneous coronary intervention was performed in 23 patients (35%) of the FFR-guided group and 90 patients (57%) of the angio-guided group (P < .01). In the FFR-guided group, PCI was more often performed in arterial grafts as compared with the angio-guided group (16 [70%] vs 12 [13%], respectively; P < .01). Follow-up was obtained in 96% of patients at a median of 3.8 years (1.6-4.0 years). At multivariate analysis, major adverse cardiac and cerebrovascular event rate was significantly lower in the FFR-guided group as compared with the angio-guided group (18 [28%] vs 77 [51%], hazard ratio 0.33 [0.11-0.96], P = .043]. Procedure costs were overall reduced in the FFR-guided group (€2240 ± €652 vs €2416 ± €522, P = .03).

CONCLUSIONS

An FFR-guided PCI of intermediate stenosis in bypass grafts is safe and results in better clinical outcomes as compared with an angio-guided PCI. This clinical benefit is achieved with a significant overall reduction in procedural costs.

Cardiopoietic stem cell therapy in heart failure: the C-CURE (Cardiopoietic stem Cell therapy in heart failURE) multicenter randomized trial with lineage-specified biologics

OBJECTIVES

This study sought to evaluate the feasibility and safety of autologous bone marrow-derived and cardiogenically oriented mesenchymal stem cell therapy and to probe for signs of efficacy in patients with chronic heart failure.

BACKGROUND

In pre-clinical heart failure models, cardiopoietic stem cell therapy improves left ventricular function and blunts pathological remodeling.

METHODS

The C-CURE (Cardiopoietic stem Cell therapy in heart failURE) trial, a prospective, multicenter, randomized trial, was conducted in patients with heart failure of ischemic origin who received standard of care or standard of care plus lineage-specified stem cells. In the cell therapy arm, bone marrow was harvested and isolated mesenchymal stem cells were exposed to a cardiogenic cocktail. Derived cardiopoietic stem cells, meeting release criteria under Good Manufacturing Practice, were delivered by endomyocardial injections guided by left ventricular electromechanical mapping. Data acquisition and analysis were performed in blinded fashion. The primary endpoint was feasibility/safety at 2-year follow-up. Secondary endpoints included cardiac structure/function and measures of global clinical performance 6 months post-therapy.

RESULTS

Mesenchymal stem cell cocktail-based priming was achieved for each patient with the dose attained in 75% and delivery without complications in 100% of cases. There was no evidence of increased cardiac or systemic toxicity induced by cardiopoietic cell therapy. Left ventricular ejection fraction was improved by cell therapy (from 27.5 ± 1.0% to 34.5 ± 1.1%) versus standard of care alone (from 27.8 ± 2.0% to 28.0 ± 1.8%, p < 0.0001) and was associated with a reduction in left ventricular end-systolic volume (-24.8 ± 3.0 ml vs. -8.8 ± 3.9 ml, p < 0.001). Cell therapy also improved the 6-min walk distance (+62 ± 18 m vs. -15 ± 20 m, p < 0.01) and provided a superior composite clinical score encompassing cardiac parameters in tandem with New York Heart Association functional class, quality of life, physical performance, hospitalization, and event-free survival.

CONCLUSIONS

The C-CURE trial implements the paradigm of lineage guidance in cell therapy. Cardiopoietic stem cell therapy was found feasible and safe with signs of benefit in chronic heart failure, meriting definitive clinical evaluation. (C-Cure Clinical Trial; NCT00810238).

Novel antiplatelet agents: ALX-0081, a Nanobody directed towards von Willebrand factor

This manuscript reviews the studies performed with ALX-0081 (INN: caplacizumab), a Nanobody targeting von Willebrand factor, in the context of current antithrombotic therapy in coronary artery disease. ALX-0081 specifically inhibits platelet adhesion to the vessel wall, and may control platelet aggregation and subsequent clot formation without increasing bleeding risk. A substantial number of antithrombotics are aimed at this cascade; however, their generally indiscriminative mode of action can result in a narrow therapeutic window, defined by the risk for bleeding complications, and thrombotic events. Nonclinically, ALX-0081 compared favorably to several antithrombotics. In Phase I studies in healthy subjects and stable angina patients undergoing percutaneous coronary intervention (PCI), ALX-0081 was well tolerated, and effectively inhibited pharmacodynamic markers. Following these results, a phase II study was initiated in high-risk acute coronary syndrome patients undergoing PCI. Based on its mechanism of action, ALX-0081 is also being developed for acquired thrombotic thrombocytopenic purpura.

Unbiased plasma proteomics for novel diagnostic biomarkers in cardiovascular disease: identification of quiescin Q6 as a candidate biomarker of acutely decompensated heart failure

AIMS

Biochemical marker testing has improved the evaluation and management of patients with cardiovascular diseases over the past decade. Natriuretic peptides (NPs), used in clinical practice to assess cardiac dysfunction, exhibit many limitations, however. We used an unbiased proteomics approach for the discovery of novel diagnostic plasma biomarkers of heart failure (HF).

METHODS AND RESULTS

A proteomics pipeline adapted for very low-abundant plasma proteins was applied to clinical samples from patients admitted with acute decompensated HF (ADHF). Quiescin Q6 (QSOX1), a protein involved in the formation of disulfide bridges, emerged as the best performing marker for ADHF (with an area under the receiver operator characteristic curve of 0.86, 95% confidence interval: 0.79-0.92), and novel isoforms of NPs were also identified. Diagnostic performance of QSOX1 for ADHF was confirmed in 267 prospectively collected subjects of whom 76 had ADHF. Combining QSOX1 to B-type NP (BNP) significantly improved diagnostic accuracy for ADHF by particularly improving specificity. Using thoracic aortic constriction in rats, QSOX1 was specifically induced within both left atria and ventricles at the time of HF onset.

CONCLUSION

The novel biomarker QSOX1 accurately identifies ADHF, particularly when combined with BNP. Through both clinical and experimental studies we provide lines of evidence for a link between ADHF and cardiovascular production of QSOX1.

Galphas-biased beta2-adrenergic receptor signaling from restoring synchronous contraction in the failing heart

Cardiac resynchronization therapy (CRT), in which both ventricles are paced to recoordinate contraction in hearts that are dyssynchronous from conduction delay, is the only heart failure (HF) therapy to date to clinically improve acute and chronic function while also lowering mortality. CRT acutely enhances chamber mechanical efficiency but chronically alters myocyte signaling, including improving β-adrenergic receptor reserve. We speculated that the latter would identify unique CRT effects that might themselves be effective for HF more generally. HF was induced in dogs by 6 weeks of atrial rapid pacing with (HFdys, left bundle ablated) or without (HFsyn) dyssynchrony. We used dyssynchronous followed by resynchronized tachypacing (each 3 weeks) for CRT. Both HFdys and HFsyn myocytes had similarly depressed rest and β-adrenergic receptor sarcomere and calcium responses, particularly the β2-adrenergic response, whereas cells subjected to CRT behaved similarly to those from healthy controls. CRT myocytes exhibited suppressed Gαi signaling linked to increased regulator of G protein (heterotrimeric guanine nucleotide-binding protein) signaling (RGS2, RGS3), yielding Gαs-biased β2-adrenergic responses. This included increased adenosine cyclic AMP responsiveness and activation of sarcoplasmic reticulum-localized protein kinase A. Human CRT responders also showed up-regulated myocardial RGS2 and RGS3. Inhibition of Gαi (with pertussis toxin, RGS3, or RGS2 transfection), stimulation with a Gαs-biased β2 agonist (fenoterol), or transient (2-week) exposure to dyssynchrony restored β-adrenergic receptor responses in HFsyn to the values obtained after CRT. These results identify a key pathway that is triggered by restoring contractile synchrony and that may represent a new therapeutic approach for a broad population of HF patients.

Long-term clinical outcome after fractional flow reserve-guided percutaneous coronary revascularization in patients with small-vessel disease

BACKGROUND

Small coronary vessels supply small myocardial territories. The clinical significance of small-vessel stenoses is therefore questionable. Moreover, percutaneous coronary intervention (PCI) of nonfunctionally significant lesions does not improve clinical outcome and might be associated with potential procedural or stent related risks. The aim of this study was to assess the clinical outcome of fractional flow reserve (FFR)-guided PCI in the treatment of small coronary vessel lesions as compared with an angio-guided PCI.

METHODS AND RESULTS

From January 2004 to December 2008, all patients treated with PCI for stable or unstable angina in small native coronary vessels (reference vessel diameter and stent size <3 mm) were retrospectively analyzed. Patients were divided into angio-guided and an FFR-guided PCI groups. A total of 717 patients were enrolled (495 angio-guided, 222 FFR-guided). End points were death, nonfatal myocardial infarction (MI), combined death or nonfatal MI, target vessel revascularization (TVR), and procedure costs. Major adverse cardiac events (MACE) were defined as death, nonfatal MI, and TVR. Clinical follow-up was obtained in 97.5% (median follow-up: 3.3 [from 0.01-5] years) of the patients. Seventy-eight patients (35%) had a significant FFR (<0.80) and underwent PCI. Using a propensity score adjusted Cox analysis, patients treated with FFR-guided PCI had significantly lower combined death or nonfatal MI (hazard ratio [HR], 0.413; 95% confidence interval [CI], 0.227-0.750; P=0.004), nonfatal MI (HR, 0.063; 95% CI, 0.009-0.462; P=0.007), TVR (HR, 0.517; 95% CI, 0.323-0.826; P=0.006), and MACE (HR, 0.458; 95% CI, 0.310-0.679; P<0.001). No difference was observed in mortality alone (HR, 0.684; 95% CI, 0.355-1.316; P=0.255). Procedure costs were also reduced in the FFR guided strategy (3253±102 Euros versus 4714±37 Euros, P<0.0001).

CONCLUSIONS

FFR-guided PCI of small coronary arteries is safe and results in better clinical outcomes when compared with an angio-guided PCI.

Transcriptional fingerprint of human whole blood at the site of coronary occlusion in acute myocardial infarction

AIMS

Transcriptome patterns associated with acute myocardial infarction at the site of coronary occlusion are largely unknown. The aim of this study was to decipher the angiogenic, atherosclerotic, and inflammatory mRNA profiles in whole blood samples collected at the site of coronary occlusion in patients with ST-elevation myocardial infarction (STEMI).

METHODS AND RESULTS

In five consecutive patients with STEMI, blood was sampled at the site of occlusion (local) and in the systemic circulation (peripheral) during primary percutaneous coronary intervention. RNA was extracted from whole blood samples. Among 221 genes involved in angiogenesis, inflammation and atherosclerosis, 24 were shown to be differentially modulated locally, by analysis with custom-designed DNA array technology. Validation in 28 distinct STEMI patients using real-time quantitative PCR identified seven out of these 24 genes to be consistently and significantly upregulated in local versus peripheral blood (p<0.05). Three genes were chemokine family members (CCL2, CCL18 and CXCL12), three genes belonged to the cell-cell and cell-extracellular matrix family (FN1, CDH5 and SPP1), and one gene was representative of the lipoprotein family (APOE).

CONCLUSIONS

We identified a set of whole blood transcripts induced at the site of coronary occlusion in the acute phase of myocardial infarction. Resolved genes indicate a predominant role for chemokines, cell-extracellular matrix, and lipoprotein alterations in the pathophysiology of acute myocardial infarction and the initial response to myocardial injury.

Long-term clinical outcome in patients with small vessel disease treated with drug-eluting versus bare-metal stenting

BACKGROUND

DES is superior to BMS in reducing restenosis and repeat revascularization. Available data are less convincing in small vessel disease. Aim of our study is to assess long-term clinical outcome of drug-eluting stents (DES) vs. bare-metal stents (BMS) in small coronary vessel disease.

METHODS

Procedural and long-term clinical outcomes were assessed in consecutive patients (pts) treated with stenting of native small coronary arteries (reference vessel diameter and implanted stent < 3mm).

RESULTS

Pts enrolled were 645: DES group (n = 277) presented more frequently diabetes (173 [62%] vs. 32 [9%], P < .0001), higher body mass index (27 ± 5 vs. 26 ± 4, P = .01) and with previous PCI (115 [42%] vs. 118 [32%], P = .01) as compared to BMS group (n=368). DES group presented more frequently with unstable angina (46 [17%] vs. 38 [10%], P = .02); BMS group presented more frequently with myocardial infarction (103 [28] vs. 43 [15], P = .0002). Reference vessel (2.27 ± 0.36 vs. 2.24 ± 0.36, P = .29), minimal lumen (0.81 ± 0.32 vs. 0.80 ± 0.31, P = .84) and stent diameter (2.59 ± 0.17 vs. 2.60 ± 0.15, P = .69) did not differ between the 2 groups. Lesion length was significantly higher in DES group (15.85 ± 6.81 vs. 13.66 ± 7.18, P = .01). At a median clinical follow-up of 3.0 years (IQR range 2.2-4.6), pts with DES showed significantly lower major adverse cardiac events (MACE, HR 0.51, 95%CI 0.33-0.78) and target vessel revascularization (TVR, HR 0.44, 95%CI 0.25-0.78). No differences were observed between the two groups as to death, myocardial infarction and stent thrombosis.

CONCLUSIONS

In small vessel disease, DES was more frequently implanted in pts at higher risk of restenosis, though it demonstrated to be more effective than BMS in reducing MACE and TVR at long-term follow-up.

Dipeptidyl peptidase IV inhibition improves cardiorenal function in overpacing-induced heart failure

AIMS

Recent studies indicate that brain natriuretic peptide (BNP(1-32)) may be truncated into BNP(3-32) by dipeptidyl peptidase IV (DPP4) and that BNP(3-32) has reduced biological activities compared with BNP(1-32). We investigated if DPP4 contributes to the cardiorenal alterations and to the attenuated response to BNP seen in heart failure.

METHODS AND RESULTS

Haemodynamic and renal assessment was performed in 12 pigs at baseline, 4 weeks after pacing-induced heart failure, and during BNP infusion. They were randomized to either placebo or treatment with a DPP4 inhibitor, sitagliptin. After 4 weeks of pacing, heart rate was reduced compared with baseline in the sitagliptin group (60 ± 2 vs. 95 ± 16 b.p.m., P < 0.01), and an increase in stroke volume was observed in the sitagliptin group compared with placebo (+24 ± 6% vs. -17 ± 7%, P < 0.01). Glomerular filtration rate declined at week 4 compared with baseline in the placebo group (1.3 ± 0.4 vs. 2.3 ± 0.3 mL/kg/min, P < 0.01) but remained preserved in the sitagliptin group [1.8 ± 0.2 vs. 2.0 ± 0.3 mL/kg/min, P = NS (non-significant)]. In the sitagliptin group, BNP infusion improved end-systolic elastance (68 ± 5 vs. 31 ± 4 mmHg/kg/mL, P < 0.05), ventricular-arterial coupling, and mechanical efficiency. Compared with controls (n = 6), myocardial gene expression of BNP, interleukin-6, Na(+)-Ca(2+) exchanger, and calmodulin was up-regulated in the placebo group, but not in the sitagliptin group.

CONCLUSION

In pacing-induced heart failure, DPP4 inhibition preserves the glomerular filtration rate, modulates stroke volume and heart rate, and potentiates the positive inotropic effect of exogenous BNP at no energy expense.

Acalculous cholecystitis and tamponade: an unusual combination?

Although pericardial effusion is a well-known feature of Churg-Strauss syndrome, cardiac tamponade has rarely been encountered. The present report describes a case of Churg-Strauss syndrome that presented as an acute cholecystitis and was complicated by tamponade. Histopathological exam of both pericardium and gall bladder was conclusive for Churg-Strauss syndrome.

Adult stem cells in the treatment of acute myocardial infarction

Stem cell therapy has emerged as a novel therapeutic treatment alternative for early and end stage LV dysfunction. The rapid translation into clinical trials has left many questions unanswered. Moreover, results of randomized trials in the setting of acute myocardial infarction are controversial, emphasizing a need for further basic and translational research to improve understanding of cell functionality. This review attempts to summarize some of the functional issues related to cell therapy and also evaluate the current status of stem cell clinical trials. Although results to date have shown modest improvement in left ventricular function, the progress should follow a coordinated, multidisciplinary, and well designed path to address issues of cell homing, cell retention, and also look at outcomes beyond physiological parameters.

Effective radiation dose, time, and contrast medium to measure fractional flow reserve

OBJECTIVES

This study sought to define the additional effective radiation dose, procedural time, and contrast medium needed to obtain fractional flow reserve (FFR) measurements after a diagnostic coronary angiogram.

BACKGROUND

The FFR measurements performed at the end of a diagnostic angiogram allow the obtaining of functional information that complements the anatomic findings.

METHODS

In 200 patients (mean age 66 +/- 10 years) undergoing diagnostic coronary angiography, FFR was measured in at least 1 intermediate coronary artery stenosis. Hyperemia was achieved by intracoronary (n = 180) or intravenous (n = 20) adenosine. The radiation dose (mSv), procedural time (min), and contrast medium (ml) needed for diagnostic angiography and FFR were recorded.

RESULTS

A total of 296 stenoses (1.5 +/- 0.7 stenoses per patient) were assessed. The additional mean radiation dose, procedural time, and contrast medium needed to obtain FFR expressed as a percentage of the entire procedure were 30 +/- 16% (median 4 mSv, range 2.4 to 6.7 mSv), 26 +/- 13% (median 9 min, range 7 to 13 min), and 31 +/- 16% (median 50 ml, range 30 to 90 ml), respectively. The radiation dose and contrast medium during FFR were similar after intravenous and intracoronary adenosine, though the procedural time was slightly longer with intravenous adenosine (median 11 min, range 10 to 17 min, p = 0.04) than with intracoronary adenosine (median 9 min, range 7 to 13 min). When FFR was measured in 3 or more lesions, radiation dose, procedural time, and contrast medium increased.

CONCLUSIONS

The additional radiation dose, procedural time, and contrast medium to obtain FFR measurement are low as compared to other cardiovascular imaging modalities. Therefore, the combination of diagnostic angiography and FFR measurements is warranted to provide simultaneously anatomic and functional information in patients with coronary artery disease.

Comparison of 600 versus 300-mg Clopidogrel loading dose in patients with ST-segment elevation myocardial infarction undergoing primary coronary angioplasty

The aim of the present study was to compare 600- and 300-mg clopidogrel loading doses in patients with ST-segment elevation myocardial infarctions who underwent primary percutaneous coronary intervention (PCI). Two hundred fifty-five consecutive patients presenting with ST-segment elevation myocardial infarctions who underwent primary PCI were enrolled. Patients were divided into 2 groups on the basis of the loading dose of clopidogrel received before the procedure (600 vs 300 mg). Procedural angiographic end points and 1-year major adverse cardiac events were compared between the 2 groups. Major adverse cardiac events were defined as death, nonfatal myocardial infarction, and target vessel revascularization. There were no significant differences in baseline clinical and angiographic features between the 2 groups: 157 (62%) in the clopidogrel 600 mg group and 98 (38%) in the 300 mg group. Patients receiving 600-mg loading dose of clopidogrel showed a significantly lower incidence of post-PCI myocardial blush grade 0 or 1 (odds ratio 0.64, 95% confidence interval 0.43 to 0.96, p = 0.03) and significantly less common no-reflow phenomenon (odds ratio 0.38, 95% confidence interval 0.15 to 0.98, p = 0.04) compared to those in the 300-mg group. Propensity-adjusted Cox analysis showed significantly higher survival free of major adverse cardiac events in patients receiving 600-mg loading dose of clopidogrel compared to those receiving the lower dose (hazard ratio 0.57, 95% confidence interval 0.33 to 0.98, p = 0.04). In conclusion, a 600-mg loading dose of clopidogrel is associated with improvements in procedural angiographic end points and 1-year clinical outcomes in patients with ST-segment elevation myocardial infarction who undergo primary PCI compared to a 300-mg dose.

Thrombus aspiration in primary percutaneous coronary intervention in high-risk patients with ST-elevation myocardial infarction: a real-world registry

OBJECTIVES

To evaluate the effect of thrombus aspiration in a real-world all-comer patient population with STEMI undergoing primary PCI.

BACKGROUND

Catheter thrombus aspiration in primary PCI was beneficial in randomized clinical trials.

METHODS

We enrolled 313 STEMI patients presenting with TIMI Flow Grade 0 or 1 in the infarct related artery at baseline angiogram undergoing primary PCI. PATIENTS were divided in two groups based on whether thrombus aspiration was attempted. This decision was left at operator's discretion. Procedural and long-term clinical outcomes were compared between the two groups.

RESULTS

Baseline characteristics were similar between groups: 194 (62%) received thrombus aspiration and 119 underwent conventional PCI. Thrombus aspiration was associated with significantly lower post-PCI TIMI Frame Count values (19 +/- 15 vs. 25 +/- 17; P = 0.002) and higher TIMI Flow Grade 3 (92% vs. 73%; P < 0.001). Postprocedural myocardial perfusion assessed by myocardial blush grade (MBG) was significantly increased in the thrombus aspiration group (MBG 3: 44% vs. 21%; P < 0.001). No significant difference was found between the two groups in clinical outcome at 30 days. At one year, patients treated with thrombus aspiration showed significantly higher overall survival (HR 0.41, 95% CI 0.20-0.81; log-rank P = 0.010) and MACE-free survival (HR 0.49, 95% CI 0.28-0.85; log-rank P = 0.011).

CONCLUSIONS

In real-world all-comer STEMI patients with occluded infarct-related artery, thrombus aspiration prior to PCI improves coronary flow, myocardial perfusion, and long-term clinical outcome as compared with PCI in the absence of thrombus aspiration.

B-type natriuretic peptide as a marker of heart failure: new insights from biochemistry and clinical implications

The mature, biologically active 32-amino acid long B-type natriuretic peptide (BNP(1-32)), is cleaved by corin from the BNP prohormone. Recent data demonstrated that BNP(1-32) might be an ideal substrate for the endogenous aminopeptidase, dipeptidyl-peptidase (DPP) IV. DPP IV removes the two amino-terminal amino acids (Ser and Pro) from BNP(1-32) to produce BNP(3-32), which has been detected in plasma of patients with heart failure. In a canine model, intravenous BNP(3-32) infusion resulted in less natriuresis, diuresis and vasodilation compared to intravenous infusion of BNP(1-32). The clinical relevance of these observations may be important for patients with high plasma BNP concentrations, which can be measured by commercially available immunoassays. Further studies are needed to explore whether DPP IV inhibitors increase the bioavailability of BNP(1-32), delay the progression of heart failure and increase the efficacy of exogenously administered BNP(1-32) in decompensated heart failure.

Quantitative assessment of coronary microvascular function in patients with and without epicardial atherosclerosis

AIMS

The influence of atherosclerosis and its risk factors on coronary microvascular function remain unclear as current methods of assessing microvascular function do not specifically test the microcirculation in isolation. We examined the influence of epicardial vessel atherosclerosis on coronary microvascular function using the index of myocardial resistance (IMR).

METHODS AND RESULTS

IMR (a measure of microvascular function) and fractional flow reserve (FFR, a measure of the epicardial compartment) were measured in 143 coronary arteries (116 patients). Fifteen patients (22 arteries, mean age 48+/-16 years) had no clinical evidence of atherosclerosis (control group). One hundred and one patients (121 arteries, mean age 63+/-11 years) had established atherosclerosis and multiple cardiovascular risk factors (atheroma group). Mean IMR in the control group (19+/-5, range 8-28) was significantly lower than in the atheroma group (25+/-13, range 6-75) (P<0.01). However, there was large overlap between IMR in both groups, with 69% of IMR values in patients with atheroma being within the control range. Mean FFR was also higher in the control group (0.96+/-0.02, range 0.93-1.00) than in the atheroma group (0.85+/-0.14, range 0.19-1.00) (P<0.01). There was no correlation between IMR and FFR (r=0.09; P=0.24), even when results in the control (r=0.02; P=0.92) and atheroma (r=0.15; P=0.10) groups were analysed in isolation. Using stepwise multiple regression analysis presence/absence of atheroma (ss=0.42; P=0.02) was the only independent determinant of IMR.

CONCLUSIONS

Mean IMR is higher in patients with epicardial atherosclerosis. However, there is a large overlap between IMR in patients with and without epicardial atherosclerosis.

Continuous monitoring of intrathoracic impedance and right ventricular pressures in patients with heart failure

BACKGROUND

Hemodynamic monitoring using implantable devices may provide early warning of volume overload in patients with heart failure (HF). This study was designed to prospectively compare information from intrathoracic impedance monitoring and continuous right ventricular pressure measurements in patients with HF.

METHODS AND RESULTS

Sixteen patients with HF (age, 63.5+/-13.8 years; left ventricular ejection fraction, 23.2+/-11.3%; New York Heart Association, II and III) and a previous HF decompensation received both a cardiac resynchronization therapy defibrillator providing a daily average of intrathoracic impedance and an implantable hemodynamic monitor providing an estimate of the pulmonary artery diastolic pressure. At the end of a 6-month investigator-blinded period, baseline reference hemodynamic values were determined over 4 weeks during which the patient was clinically stable. A major HF event was defined as HF decompensation requiring hospitalization, IV diuretic treatment, or leading to death. Sixteen major HF events occurred in 10 patients. Within 30 days and 14 days before a major HF event, impedance decreased by 0.12+/-0.21 Omega/d and 0.20+/-0.20 Omega/d, respectively, whereas estimated pulmonary arterial diastolic pressure increased by 0.10+/-0.20 mm Hg/d and 0.16+/-0.15 mm Hg/d, respectively. During these periods, impedance decreased by 3.8+/-5.4 Omega (P<0.02) and 4.9+/-6.1 Omega (P<0.007), respectively, whereas estimated pulmonary arterial diastolic pressure increased by 5.8+/-5.7 mm Hg (P<0.002) and 6.8+/-6.1 mm Hg (P<0.001), respectively, compared with baseline. In all patients, impedance and estimated pulmonary arterial diastolic pressure were inversely correlated (r = -0.48+/-0.25). Within 30 days preceding a major HF event, this correlation improved to r =-0.58+/-0.24.

CONCLUSIONS

Decompensated HF develops based on hemodynamic derangements and is preceded by significant changes in intrathoracic impedance and right ventricular pressures during the month prior to a major clinical event. Impedance and pressure changes are moderately correlated. Future research may establish the complementary contribution of both parameters to guide diagnosis and management of patients with HF by implantable devices.

Long-term clinical outcome after fractional flow reserve-guided treatment in patients with angiographically equivocal left main coronary artery stenosis

BACKGROUND

Significant left main coronary artery stenosis is an accepted indication for surgical revascularization. The potential of angiography to evaluate the hemodynamic severity of a stenosis is limited. The aims of the present study were to assess the long-term clinical outcome of patients with an angiographically equivocal left main coronary artery stenosis in whom the revascularization strategy was based on fractional flow reserve (FFR) and to determine the relationship between quantitative coronary angiography and FFR.

METHODS AND RESULTS

In 213 patients with an angiographically equivocal left main coronary artery stenosis, FFR measurements and quantitative coronary angiography were performed. When FFR was > or =0.80, patients were treated medically or another stenosis was treated by coronary angioplasty (nonsurgical group; n=138). When FFR was <0.80, coronary artery bypass grafting was performed (surgical group; n=75). The 5-year survival estimates were 89.8% in the nonsurgical group and 85.4% in the surgical group (P=0.48). The 5-year event-free survival estimates were 74.2% and 82.8% in the nonsurgical and surgical groups, respectively (P=0.50). Percent diameter stenosis at quantitative coronary angiography correlated significantly with FFR (r=-0.38, P<0.001), but a very large scatter was observed. In 23% of patients with a diameter stenosis <50%, the left main coronary artery stenosis was hemodynamically significant by FFR.

CONCLUSIONS

In patients with equivocal stenosis of the left main coronary artery, angiography alone does not allow appropriate individual decision making about the need for revascularization and often underestimates the functional significance of the stenosis. The favorable outcome of an FFR-guided strategy suggests that FFR should be assessed in such patients before a decision is made "blindly" about the need for revascularization.

Predictors of improvement of unrepaired moderate ischemic mitral regurgitation in patients undergoing elective isolated coronary artery bypass graft surgery

BACKGROUND

The persistence of moderate ischemic mitral regurgitation (IMR) after isolated coronary artery bypass graft surgery is an important independent predictor of long-term mortality. The aim of the present study was to identify predictors of postoperative improvement in moderate IMR in patients with ischemic heart disease undergoing elective isolated coronary artery bypass graft surgery.

METHODS AND RESULTS

The study population consisted of 135 patients with ischemic heart disease (age, 65+/-9 years; 81% male) and moderate IMR undergoing isolated coronary artery bypass graft surgery. Fourteen patients died before the 12-month follow-up echocardiography and were excluded. At the 12-month follow-up, 57 patients showed no or mild IMR (improvement group), whereas 64 patients failed to improve (failure group). Before coronary artery bypass graft surgery, the improvement group had significantly more viable myocardium and less dyssynchrony between papillary muscles than the failure group (P<0.001). All other preoperative parameters were similar in both groups. Large extent (> or =5 segments) of viable myocardium (odds ratio, 1.45; 95% confidence interval, 1.22 to 1.89; P<0.001) and absence (<60 ms) of dyssynchrony (odds ratio, 1.49; 95% confidence interval, 1.29 to 1.72; P<0.001) were independently associated with improvement in IMR. The majority (93%) of patients with viable myocardium and an absence of dyssynchrony showed an improvement in IMR. In contrast, only 34% and 18% of patients with dyssynchrony and nonviable myocardium, respectively, showed an improvement in IMR, whereas 32% and 49%, respectively, of these patients showed worsening of IMR (P<0.001).

CONCLUSIONS

Reliable improvement in moderate IMR by isolated coronary artery bypass graft surgery was observed only in patients with concomitant presence of viable myocardium and absence of dyssynchrony between papillary muscles.

Percutaneous Transvenous Mitral Annuloplasty

Background— We assessed the safety and feasibility of permanent implantation of a novel coronary sinus mitral repair device (PTMA, Viacor Inc).

Methods and Results— Symptomatic (New York Heart Association class 2 or 3) patients with primarily functional mitral regurgitation (MR) were included. A diagnostic PTMA procedure was performed in the coronary sinus venous continuity. MR was assessed and the PTMA device adjusted to optimize efficacy. If MR reduction (≥1 grade) was observed, placement of a PTMA implant was attempted. Implanted patients were evaluated with echocardiographic, quality of life, and exercise capacity metrics. Nineteen patients received a diagnostic PTMA study. Diagnostic PTMA was effective in 13 patients (MR grade 3.2�0.6 reduced to 2.0�1.0), and PTMA implants were placed in 9 patients. Four devices were removed uneventfully (7, 84, 197, and 216 days), 3 for annuloplasty surgery due to observed PTMA device migration and/or diminished efficacy. No procedure or device-related major adverse events with permanent sequela were observed in any of the diagnostic or implant patients. Sustained reductions of mitral annulus septal-lateral dimension from 3D echo reconstruction dimensions were observed (4.0�1.2 mm at 3 months).

Conclusions— Percutaneous implantation of the PTMA device is feasible and safe. Acute results demonstrate a possibly meaningful reduction of MR in responding patients. Sustained favorable geometric modification of the mitral annulus has been observed, though reduction of MR has been limited. The PTMA method warrants continued evaluation and development.

Severity of coronary arterial stenoses responsible for acute coronary syndromes

Acute myocardial infarctions were generally believed to result from plaque rupture and thrombosis at the site of a "mild to moderate" coronary stenosis. To assess the severity of coronary stenoses that predisposed to acute coronary syndrome, the 317 patients prospectively included were (1) 102 patients with acute ST-elevation myocardial infarction (STEMI) referred for primary percutaneous coronary intervention (PCI), (2) 135 patients with non-STEMI or unstable angina pectoris (UAP) referred for semiurgent PCI, and (3) 80 patients with stable angina pectoris (SAP) admitted for elective PCI. Patients with STEMI were included if thrombus aspiration could restore normal antegrade coronary blood flow. After aspiration (but before PCI), a high-quality angiogram was obtained and the reference diameter, minimal luminal diameter, and percentage of diameter stenosis of the culprit lesion were quantified. In patients with non-STEMI/UAP and SAP, aspiration was not performed. Average diameter of stenosis was similar in patients with STEMI and those with SAP (66 +/- 12% vs 65 +/- 10%, respectively; p = NS), but was slightly larger in patients with non-STEMI/UAP (71 +/- 12%; p <0.05 vs both STEMI and SAP). In patients with STEMI, only 11% of culprit stenoses were found to have diameter stenosis <50% after removal of the thrombus. In conclusion, most STEMIs occurred at the site of severe coronary stenosis. Diameter stenosis severity was <50% in a minority of cases.

Human coronary atherosclerosis modulates cardiac natriuretic peptide release

Natriuretic peptides (NPs) modulate vasodilatation and vascular remodelling. In human coronary explants, expression of NPs mRNA and their respective receptors is significantly more pronounced with advanced atherosclerotic lesions.

AIMS

We hypothesize that vascular atherosclerosis modulates NP release in vivo during progressive stages of coronary atherosclerosis.

METHODS AND RESULTS

NT-proANP (A) and NT-proBNP (B) were assessed on blood samples of 194 patients. Coronary atherosclerosis was assessed in all patients by angiography and in case of moderate stenosis by fractional flow reserve (FFR), a validated tool for detecting ischemia-inducing stenosis. Significant coronary stenosis was defined as a diameter stenosis (DS) >/=50% and/or positive FFR. Endothelial dysfunction was detected by cold pressure test (CPT) in a subgroup of 99 patients. Patients were divided into: (1) normal group (normal endothelial function, n=19); (2) endothelial dysfunction group (n=17); (3) moderate atherosclerotic group (at least one coronary stenosis <50%, n=86); (4) stenotic group (n=72). A and B were higher in patients with endothelial dysfunction (A: 2951 [1290-3920] fmol/ml; B: 156 [98-170] pg/ml), moderate atherosclerotic (A: 3868 [2250-5890] fmol/ml, p<0.05 vs. normal; B: 162 [84-283] pg/ml) and stenotic group (A: 3934 [2647-5525]; B: 227 [191-784] pg/ml; p<0.05 vs. normal) as compared with normal group (A: 2378 [970-2601] fmol/ml; B: 78 [40-136] pg/ml). During CPT, a mild NT-proANP increase was observed only in patients with endothelial dysfunction (Delta% vs. baseline: 17+/-6, p<0.05). NT-proBNP did not change after CPT in all groups.

CONCLUSION

Well defined stages of atherosclerosis are characterized by progressive increases in NT-proANP and NT-proBNP levels, beginning with endothelial dysfunction and progressively more pronounced with moderate and severe coronary atherosclerosis irrespective of the underlying myocardial disease.

Nonmyocardial production of ST2 protein in human hypertrophy and failure is related to diastolic load

OBJECTIVES

This study was designed to investigate: 1) relationships between serum ST2 levels and hemodynamic/neurohormonal variables; 2) myocardial ST2 production; and the 3) expression of ST2, membrane-anchored ST2L, and its ligand, interleukin (IL)-33, in myocardium, endothelium, and leukocytes from patients with left ventricular (LV) pressure overload and congestive cardiomyopathy.

BACKGROUND

Serum levels of ST2 are elevated in heart failure. The relationship of ST2 to hemodynamic variables, source of ST2, and expression of ST2L and IL-33 in the cardiovascular system are unknown.

METHODS

Serum ST2 (pg/ml; median [25th, 75th percentile]) was measured in patients with LV hypertrophy (aortic stenosis) (n = 45), congestive cardiomyopathy (n = 53), and controls (n = 23). ST2 was correlated to N-terminal pro-brain natriuretic peptide, C-reactive protein, and hemodynamic variables. Coronary sinus and arterial blood sampling determined myocardial gradient (production) of ST2. The levels of ST2, ST2L, and IL-33 were measured (reverse transcriptase-polymerase chain reaction) in myocardial biopsies and leukocytes. The ST2 protein production was evaluated in human endothelial cells. The IL-33 protein expression was determined (immunohistochemistry) in coronary artery endothelium.

RESULTS

The ST2 protein was elevated in aortic stenosis (103 [65, 165] pg/ml, p < 0.05) and congestive cardiomyopathy (194 [69, 551] pg/ml, p < 0.01) versus controls (49 [4, 89] pg/ml) and correlated with B-type natriuretic peptide (r = 0.5, p < 0.05), C-reactive protein (r = 0.6, p < 0.01), and LV end-diastolic pressure (r = 0.38, p < 0.03). The LV ST2 messenger ribonucleic acid was similar in aortic stenosis and congestive cardiomyopathy versus control (p = NS). No myocardial ST2 protein gradient was observed. Endothelial cells secreted ST2. The IL-33 protein was expressed in coronary artery endothelium. Leukocyte ST2L and IL-33 levels were highly correlated (r = 0.97, p < 0.001).

CONCLUSIONS

In human hypertrophy and failure, serum ST2 correlates with the diastolic load. Though the heart, endothelium, and leukocytes express components of ST2/ST2L/IL-33 pathway, the source of circulating serum ST2 is extra-myocardial.

Dipeptidyl-peptidase IV and B-type natriuretic peptide. From bench to bedside

B-type natriuretic peptide (BNP) has emerged as a reliable biomarker in patients with congestive heart failure. The mature, biologically active B-type natriuretic peptide, BNP

Clin Chem Lab Med 2009;47:248–52.

Inpatient monitoring and prognostic importance of B-type natriuretic peptide

Acute decompensated heart failure (ADHF) is the leading cause of hospitalization in many industrialized countries. Despite a consistent body of data demonstrating the benefits of drug therapy, the prognosis of patients admitted with ADHF remains dismal, as it is associated with high readmission and mortality rates within 6 months of admission. ADHF is a largely hemodynamic disorder; 90% of hospitalized patients present with volume overload. Neurohormonal activation characterizes the disease; the B-type natriuretic peptide (BNP) and N-terminal prohormone brain natriuretic peptide are natriuretic and vasodilating peptides released from the cardiac ventricles as a response to ventricular volume expansion and relate to outcome. While BNP levels obtained on admission provide independent prognostic information of in-hospital mortality, BNP levels during and at the completion of hospitalization can help to achieve euvolemia and may reflect adequacy of treatment. Once euvolemia is reached, BNP level correlated with functional class and prognosis. Studies using natriuretic peptides have suggested that predischarge BNP level appeared to be the strongest predictor for identifying subsequent death or hospital admission at 6 months. The addition of predischarge BNP levels to a clinical/instrumental decisional score for discharge decision should make possible the detection of high-risk patients who need reinforced treatment or follow-up.

Cardiovascular disease in patients with chronic renal impairment: role of natriuretic peptides

Although there is overwhelming evidence that natriuretic peptides might be helpful in the diagnosis and management of congestive heart failure patients, the relationship among brain natriuretic peptides (BNP), renal function, and the severity of heart failure is less clear. It is obvious that the metabolism and elimination of BNP and N-terminal prohormone brain natriuretic peptide (NT-proBNP) are different with BNP clearance less dependent upon renal function. This paper reviews current data about the diagnostic and predictive role of natriuretic peptides to detect cardiac events in patients with chronic kidney disease. Although BNP and Nt-proBNP can be used to diagnose acute heart failure and may help predict risk and future cardiac events in patients with chronic kidney disease (CKD), a strategy that incorporates their use in daily clinical practice is still lacking.