Combined Cardiac Damage Staging by Echocardiography and Cardiac Catheterization in Patients With Clinically Significant Aortic Stenosis

BACKGROUND

Cardiac damage (CD) staging enhances risk stratification in patients with clinically significant aortic stenosis (AS). We aimed to assess the prognostic value and reclassification rate of right heart catheterization (RHC) compared with transthoracic echocardiography (TTE) in characterising CD staging at 3-year follow-up in patients with clinically significant AS, to identify patients that would benefit from RHC for prognostic stratification, and to test the prognostic value of combined CD staging.

METHODS

An observational cohort study of 432 AS patients undergoing TTE and RHC were divided into moderate or asymptomatic severe (m/asAS) and symptomatic severe (ssAS) AS. Kaplan-Meier curves were used to compare survival. The accuracy in prognostic stratification was tested by area under the receiver operating characteristic curve analysis and Delong test.

RESULTS

In both cohorts, TTE- and RHC-derived staging systems had prognostic value, although the agreement between them appeared moderate. A higher proportion of patients were assigned to stage 2 by TTE than by RHC. Patients in TTE-derived stage 2 had a high reclassification rate, with 40%-50% presenting with right chamber involvement (stages 3-4) according to RHC. Discordant cases were significantly older, with higher prevalence of atrial fibrillation, markedly elevated N-terminal pro-B-type natriuretic peptide, and higher indexed left atrial volume, E/e', and systolic pulmonary artery pressure vs concordant cases (P < 0.05). The combined CD staging, integrating TTE and RHC, was more accurate in predicting mortality than the TTE-derived system (P < 0.05).

CONCLUSIONS

In patients with m/asAS and ssAS, the combined CD staging, derived from TTE and RHC, was more accurate in predicting mortality than TTE alone. In a subset of AS patients, the integration of RHC may significantly improve prognostic stratification.

Predictors of percutaneous coronary intervention derived from CCTA in patients with chronic coronary syndrome

BACKGROUND

To identify anatomical and morphological plaque features predictors of PCI and create a multiparametric score to increase the predictive yield. Moreover, we assessed the incremental predictive value of FFRCT (Fractional Flow Reserve derived from CCTA) trans-lesion gradient (ΔFFRCT) when integrated into the score.

METHODS

Observational cohort study including patients undergoing CCTA for suspected coronary artery disease, with FFRCT available, referred to invasive coronary angiogram and assessment of fractional flow reserve. Plaque analysis was performed using validated semi-automated software. Logistic regression was performed to identify anatomical and morphological plaque features predictive of PCI. Optimal thresholds were defined by area under the receiver-operating characteristics curve (AUC) analysis. A scoring system was developed in a derivation cohort (70 ​% of the study population) and tested in a validation cohort (30 ​% of patients).

RESULTS

The overall study population included 340 patients (455 vessels), among which 238 patients (320 vessels) were included in the derivation cohort. At multivariate logistic regression analysis, absence of left main disease, diameter stenosis (DS), non-calcified plaque (NCP) volume, and percent atheroma volume (PAV) were independent predictors of PCI. Optimal thresholds were: DS ​≥ ​50 ​%, volume of NCP>113 ​mm3 and PAV>17 ​%. A weighted score (CT-PCI Score) ranging from 0 to 11 was obtained. The AUC of the score was 0.80 (95%CI 0.74-0.86). The integration of ΔFFRCT in the CT-PCI score led to a mild albeit not significant increase in the AUC (0.82, 95%CI 0.77-0.87, p ​= ​0.328).

CONCLUSIONS

Plaque anatomy and morphology derived from CCTA could aid in identifying patients amenable to PCI.

Transcatheter aortic valve implantation versus surgical aortic valve replacement in severe aortic stenosis patients at low surgical mortality risk: a cost-effectiveness analysis in Belgium

BACKGROUND

Transcatheter aortic valve implantation (TAVI) with the SAPIEN 3 device has recently shown significant clinical benefits, compared to surgical aortic valve replacement (SAVR), in patients at low risk for surgical mortality (PARTNER 3 trial, NCT02675114). Currently in Belgium, TAVI use is restricted to high-risk or inoperable patients with severe symptomatic aortic stenosis (sSAS). This cost-utility analysis aimed to assess whether TAVI with SAPIEN 3 could lead to potential cost-savings compared with SAVR, in the low-risk sSAS population in Belgium.

METHODS

A previously published, two-stage, Markov-based cost-utility model was used. Clinical outcomes were captured using data from PARTNER 3 and the model was adapted for the Belgian context using cost data from the perspective of the Belgian National Healthcare System, indexed to 2022. A lifetime horizon was chosen. The model outputs included changes in direct healthcare costs, survival and health-related quality of life using TAVI versus SAVR.

RESULTS

TAVI with SAPIEN 3 provides meaningful clinical and cost benefits over SAVR, in terms of an increase in quality-adjusted life years (QALYs) of 0.94 and cost-saving of €3 013 per patient. While initial procedure costs were higher for TAVI compared with SAVR, costs related to rehabilitation, disabling stroke, treated atrial fibrillation, and rehospitalization were lower. The cost-effectiveness of TAVI over SAVR remained robust in sensitivity analyses.

CONCLUSION

TAVI with SAPIEN 3 may offer a meaningful alternative intervention to SAVR in Belgian low-risk patients with sSAS, showing both clinical benefits and cost savings associated with post-procedure patient management.

Latest Developments in Robotic Percutaneous Coronary Interventions

Since the first robotic-assisted percutaneous coronary intervention procedure (R-PCI) was performed in 2004, there has been a steady evolution in robotic technology, combined with a growth in the number of robotic installations worldwide and operator experience. This review summarises the latest developments in R-PCI with a focus on developments in robotic technology, procedural complexity, tele-stenting and training methods, which have all contributed to the global expansion in R-PCI.

Continuous vs Bolus Thermodilution to Assess Microvascular Resistance Reserve

BACKGROUND

Coronary flow reserve (CFR) and microvascular resistance reserve (MRR) can, in principle, be derived by any method assessing coronary flow.

OBJECTIVES

The aim of this study was to compare CFR and MRR as derived by continuous (CFRcont and MRRcont) and bolus thermodilution (CFRbolus and MRRbolus).

METHODS

A total of 175 patients with chest pain and nonobstructive coronary artery disease were studied. Bolus and continuous thermodilution measurements were performed in the left anterior descending coronary artery. MRR was calculated as the ratio of CFR to fractional flow reserve and corrected for changes in systemic pressure. In 102 patients, bolus and continuous thermodilution measurements were performed in duplicate to assess test-retest reliability.

RESULTS

Mean CFRbolus was higher than CFRcont (3.47 ± 1.42 and 2.67 ± 0.81 [P < 0.001], mean difference 0.80, upper limit of agreement 3.92, lower limit of agreement -2.32). Mean MRRbolus was also higher than MRRcont (4.40 ± 1.99 and 3.22 ± 1.02 [P < 0.001], mean difference 1.2, upper limit of agreement 5.08, lower limit of agreement -2.71). The correlation between CFR and MRR values obtained using both methods was significant but weak (CFR, r = 0.28 [95% CI: 0.14-0.41]; MRR, r = 0.26 [95% CI: 0.16-0.39]; P < 0.001 for both). The precision of both CFR and MRR was higher when assessed using continuous thermodilution compared with bolus thermodilution (repeatability coefficients of 0.89 and 2.79 for CFRcont and CFRbolus, respectively, and 1.01 and 3.05 for MRRcont and MRRbolus, respectively).

CONCLUSIONS

Compared with bolus thermodilution, continuous thermodilution yields lower values of CFR and MRR accompanied by an almost 3-fold reduction of the variability in the measured results.

Impact of Post-PCI FFR Stratified by Coronary Artery

BACKGROUND

Low fractional flow reserve (FFR) after percutaneous coronary intervention (PCI) has been associated with adverse clinical outcomes. Hitherto, this assessment has been independent of the epicardial vessel interrogated.

OBJECTIVES

This study sought to assess the predictive capacity of post-PCI FFR for target vessel failure (TVF) stratified by coronary artery.

METHODS

We performed a systematic review and individual patient-level data meta-analysis of randomized clinical trials and observational studies with protocol-recommended post-PCI FFR assessment. The difference in post-PCI FFR between left anterior descending (LAD) and non-LAD arteries was assessed using a random-effect models meta-analysis of mean differences. TVF was defined as a composite of cardiac death, target vessel myocardial infarction, and clinically driven target vessel revascularization.

RESULTS

Overall, 3,336 vessels (n = 2,760 patients) with post-PCI FFR measurements were included in 9 studies. The weighted mean post-PCI FFR was 0.89 (95% CI: 0.87-0.90) and differed significantly between coronary vessels (LAD = 0.86; 95% CI: 0.85 to 0.88 vs non-LAD = 0.93; 95% CI: 0.91-0.94; P < 0.001). Post-PCI FFR was an independent predictor of TVF, with its risk increasing by 52% for every reduction of 0.10 FFR units, and this was mainly driven by TVR. The predictive capacity for TVF was poor for LAD arteries (AUC: 0.52; 95% CI: 0.47-0.58) and moderate for non-LAD arteries (AUC: 0.66; 95% CI: 0.59-0.73; LAD vs non-LAD arteries, P = 0.005).

CONCLUSIONS

The LAD is associated with a lower post-PCI FFR than non-LAD arteries, emphasizing the importance of interpreting post-PCI FFR on a vessel-specific basis. Although a higher post-PCI FFR was associated with improved prognosis, its predictive capacity for events differs between the LAD and non-LAD arteries, being poor in the LAD and moderate in the non-LAD vessels.

Same Day Discharge Strategy by Default in a Tertiary Catheterization Laboratory. Value Based Healthcare-Change in Practice

AIMS

To assess the effects on outcomes and hospital revenues (societal cost) of a by default strategy of same day discharge (SDD) in patients undergoing a cardiac catheterization procedure in a Belgian Hospital.

METHODS AND RESULTS

Outcome and complete financial data were obtained in all consecutive patients with a cardiac catheterization performed in 2019 (n=5237) and in 2021 (n=5377). Patient-reported experience, patient satisfaction and Net promotor score were obtained prospectively for the SDD cohort in 2021. The proportion of patients receiving catheterization procedure in SDD increased from 28 to 44 % (p<0.001). This translates to the saving of 889 conventional hospitalizations in 2021. All-cause death and readmission rate remained unchanged (0,17% vs 0,15% (p=0,004); and 0,7% vs 1,8% (p>0,05)) in 2019 and 2021, respectively. Patients satisfaction top box score was 91% and the Net Promotor Score was 89,5. The by default SDD strategy was associated with reduction in in-hospital health care spending, on average 3206€ per procedure is saved. This means a 57% decrease in hospital revenues and translates into an important decrease in physician income.

CONCLUSION

Implementing a by default SDD cardiac catheterization strategy results in a reduction of societal cost, excellent patient satisfaction and unchanged clinical outcome. Yet, in the given context this approach negatively impacts hospital and physician revenues precluding the sustainability of such protocol.

Outcomes in patients with moderate and asymptomatic severe aortic stenosis followed up in heart valve clinics

BACKGROUND

Heart valve clinics (HVC) have been introduced to manage patients with valvular heart disease within a multidisciplinary team.

OBJECTIVE

To determine the outcome benefit of HVC approach compared with standard of care (SOC) for patients with moderate and asymptomatic severe aortic stenosis (mAS and asAS).

METHODS

Single-centre, observational registry of patients with mAS and asAS with at least one cardiac ambulatory consultation at our Cardiovascular Centre. Based on the outpatient strategy, patients were divided into HVC group, if receiving at least one visit at HVC, and SOC group, if followed by routine cardiac consultations.

RESULTS

2129 patients with mAS and asAS were divided into those followed in HVC (n=251) versus SOC group (n=1878). The mean age was 76.5±12.4 years; 919 (43.2%) had asAS. During a follow-up of 4.8±1.8 years, 822 patients (38.6%) died, 307 (14.4%) were hospitalised for heart failure and 596 (28%) underwent aortic valve replacement (AVR). After propensity score matching, the number of consultations per year, exercise stress tests, brain natriuretic peptide (BNP) determinations and CTs were higher in the HVC cohort (p<0.05 for all). A shorter time between indication of AVR and less advanced New York Heart Association class was reported in the HVC cohort (p<0.001 and p=0.032). Compared with SOC, the HVC approach was associated with reduced all-cause mortality (HR=0.63, 95% CI 0.40 to 0.98, p=0.038) and cardiovascular death (p=0.030). At multivariable analysis, the HVC remained an independent predictor of all-cause mortality (HR=0.54, 95% CI 0.34 to 0.85, p=0.007).

CONCLUSIONS

In patients with mAS and asAS, the HVC approach was associated with more efficient management and outcome benefit compared with SOC.

Reproducibility of bolus versus continuous thermodilution for assessment of coronary microvascular function in patients with ANOCA

BACKGROUND

A bolus thermodilution-derived index of microcirculatory resistance (IMR) has emerged as the standard for assessing coronary microvascular dysfunction (CMD). Continuous thermodilution has recently been introduced as a tool to quantify absolute coronary flow and microvascular resistance directly. Microvascular resistance reserve (MRR) derived from continuous thermodilution has been proposed as a novel metric of microvascular function, which is independent of epicardial stenoses and myocardial mass.

AIMS

We aimed to assess the reproducibility of bolus and continuous thermodilution in assessing coronary microvascular function.

METHODS

Patients with angina and non-obstructive coronary artery disease (ANOCA) at angiography were prospectively enrolled. Bolus and continuous intracoronary thermodilution measurements were obtained in duplicate in the left anterior descending artery (LAD). Patients were randomly assigned in a 1:1 ratio to undergo either bolus thermodilution first or continuous thermodilution first.

RESULTS

A total of 102 patients were enrolled. The mean fractional flow reserve (FFR) was 0.86±0.06. Coronary flow reserve (CFR) calculated with continuous thermodilution (CFR_cont) was significantly lower than bolus thermodilution-derived CFR (CFR_bolus; 2.63±0.65 vs 3.29±1.17; p<0.001). CFR_cont showed a higher reproducibility than CFR_bolus (variability: 12.7±10.4% continuous vs 31.26±24.85% bolus; p<0.001). MRR showed a higher reproducibility than IMR (variability 12.4±10.1% continuous vs 24.2±19.3% bolus; p<0.001). No correlation was found between MRR and IMR (r=0.1, 95% confidence interval: -0.09 to 0.29; p=0.305).

CONCLUSIONS

In the assessment of coronary microvascular function, continuous thermodilution demonstrated significantly less variability on repeated measurements than bolus thermodilution.

Diagnostic performance of exercise stress tests for detection of epicardial and microvascular coronary artery disease: the UZ Clear study

BACKGROUND

Cardiac stress tests remain the cornerstone for evaluating patients suspected of having obstructive coronary artery disease (CAD). Coronary microvascular dysfunction (CMD) can lead to abnormal non-invasive tests.

AIMS

We sought to assess the diagnostic performance of exercise stress tests with indexes of epicardial and microvascular resistance as reference.

METHODS

This was a prospective, single-arm, multicentre study of patients with an intermediate pretest probability of CAD and positive exercise stress tests who were referred for invasive angiography. Patients underwent an invasive diagnostic procedure (IDP) with measurement of fractional flow reserve (FFR) and index of microvascular resistance (IMR) in at least one coronary vessel. Obstructive CAD was defined as diameter stenosis (DS) >50% by quantitative coronary angiography (QCA). The objective was to determine the false discovery rate (FDR) of cardiac exercise stress tests with both FFR and IMR as references.

RESULTS

One hundred and seven patients (137 vessels) were studied. The mean age was 62.1±8.7, and 27.1% were female. The mean diameter stenosis was 37.2±27.5%, FFR was 0.84±0.10, coronary flow reserve was 2.74±2.07, and IMR 20.3±11.9. Obstructive CAD was present in 39.3%, whereas CMD was detected in 20.6%. The FDR was 60.7% and 62.6% with QCA and FFR as references (p-value=0.803). The combination of FFR and IMR as clinical reference reduced the FDR by 25% compared to QCA (45.8% vs 60.7%; p-value=0.006).

CONCLUSIONS

In patients with evidence of ischaemia, an invasive functional assessment accounting for the epicardial and microvascular compartments led to an improvement in the diagnostic performance of exercise tests, driven by a significant FDR reduction.

742 PROGNOSTIC IMPACT OF HIGH BLEEDING RISK IN PATIENTS WITH CALCIFIED CORONARY ARTERY DISEASE UNDERGOING ROTATIONAL ATHERECTOMY PCI

Background

Percutaneous coronary interventions (PCI) in calcified coronary artery lesions is associated with higher rate of cardiovascular adverse events and mortality.

The aim of our study was to evaluate the prognostic impact of High Bleeding Risk (HBR) condition, as defined by the Academic Research Consortium (ARC) HBR criteria, on clinical outcomes in patients with complex calcified coronary artery disease undergoing PCI after lesion preparation using Rotational Atherectomy (RA).

Methods

In this observational retrospective study, all patients with calcified coronary artery disease undergoing RA-assisted PCI between 2011 and 2021 were included. According to ARC-HBR criteria, patients were considered at HBR if at least one major criterion or two minor criteria were met. The primary endpoint was the occurrence of major adverse cardiac and cerebrovascular events (MACCE) at 4 years defined as the composite of cardiovascular death, myocardial infarction, stroke and target vessel revascularization (TVR). Secondary endpoints were cardiovascular death, bleeding events and TVR.

Results

The final population consisted of 343 patients. Median follow-up was 39 months. Among patients, 198 (57,7%) met the HBR criteria while 145 (42,7%) did not. Patients with HBR criteria were older [78.21 vs 71.68; p &lt; 0.001], with lower GFR (ml/min/1.73m2) [53.67 vs 77.51; p &lt; 0.001] and lower hemoglobin levels [Hb: g/dl; 11.93 vs 13.74; p &lt; 0.001] compare with patients without HBR. The rate of MACCE was significantly higher in patients at HBR compare with patients not at HBR (HR 1.86 [1.08-3.26]; p = 0.026) mainly driven by an increased risk of cardiovascular death. No significant differences were found concerning the rates of TVR (HR 0.48 [0.21-1.04]; p = 0.057), stroke (HR=7.7 [0.98-61.09], p=0.05) and MI (HR 2.2[0.58-8.35], p=0.241) between the two groups. Bleedings were more frequent in patients at HBR (HR 12.31 [2.93-51.64]; p &lt; 0.001) compared to patients without HBR.

Conclusion

In patients with calcified coronary artery disease PCI, despite the use of dedicated tools for optimal lesion preparation such as RA, those at HBR still present higher risk of MACCE and cardiovascular death. Conversely, rates of TVR and MI were comparable, suggesting frailty and comorbidities as primary causes of worse outcomes in patients at HBR.

Figure Legend:

Panel A: the rate of MACCE was significantly higher in patients at HBR compare with patients not at HBR (HR 1.86 [1.08-3.26]; p = 0.026),) mainly driven by an increased risk of cardiovascular death (Panel B).

Panel C: the rates of TVR were not significant different between the two groups (HR 0.48 [0.21-1.04]; p = 0.057).

Panel D: Bleedings were more frequent in patients at HBR (HR 12.31 [2.93-51.64]; p &lt; 0.001) compared to patients without HBR.

723 PREDICTORS OF PERCUTANEOUS CORONARY INTERVENTION DERIVED FROM CORONARY CT ANGIOGRAPHY IN PATIENTS WITH CHRONIC CORONARY SYNDROME

Aims

To assess whether quantitative and qualitative plaque features derived from coronary CT angiography (CCTA) could predict subsequent coronary revascularization by percutaneous coronary intervention (PCI) in patients with suspected chronic coronary syndrome (CCS).

Methods

From April 2019 to October 2020, all consecutive patients with suspected CCS undergoing CCTA and computation of Fractional Flow Reserve derived from CCTA (FFRCT), with consequent referral to coronary angiography and invasive physiological assessment, were included. The FFRCT 3D-model was used to calculate i) FFRCT value, in distal coronary segments where invasive FFR was measured, ii) trans-lesion gradient, defined as the difference in FFRCT units across the lesion derived from CTA, iii) vessel gradient, i.e., the difference in FFRCT units along the vessel. Quantitative and qualitative plaque analysis at CCTA was performed by experienced operators as recommended by current guidelines.

Results

Overall, 108 patients (143 vessels) were included. The mean age was 65±8.6 years, and 11% were diabetics. At baseline, 87 (80%) patients had chest pain. Left ventricular ejection fraction was 59±4.6%. Sixty (55.5%) patients underwent PCI, 8 (7.5%) were treated with coronary artery bypass graft (CABG), and 40 (37%) were referred to medical therapy (MT). At CCTA, the lesions undergoing PCI were significantly longer (38.85±17mm, p&lt;0.001), with more severe diameter stenosis (45.43±16.69, p=0.002), lower minimal lumen area (MLA) (2.30± 1.33mm, p=0.013), higher plaque volume (292.31±158.32mm3, p&lt;0.001), greater fibrous-fatty and necrotic core volume (18.87±20.7 and 14.78±27.42, p&lt;0.001), greater maximum calcium arc in the lesion (108.63±65.9, p&lt;0.001) and lower calcium arc the MLA (88.5±10 p=0.037) than the others referred to CABG/MT. In the PCI group, FFRCT was significantly lower (0.69± 0.11, p&lt;0.001), while trans-lesion and vessel gradients were higher (0.09±0.04 and 0.27±0.10 respectively, p&lt;0.001) than the other groups. On multivariate regression model, corrected for all confounding factors, longer lesions (OR 1.11, CI 1,01-1,21, p=0.022), higher maximum calcium arc (OR 1.02, CI 1.01-1.04, p= 0.007) and lower calcium arc at the MLA (OR 0.99, CI 0.98-0.99, p=0.031) were shown to be independent predictors of referral for PCI.

Conclusion

Lesion length and calcium arc derived from CCTA predict subsequent revascularization by PCI in patients suspected of CAD.

Microvascular dysfunction in patients with diabetes mellitus: assessment of absolute coronary flow and microvascular resistance reserve

Background

Coronary microvascular dysfunction (CMD) is an early feature of diabetic cardiomyopathy, which usually precedes the onset of systolic and diastolic dysfunction (DDF). Continuous intracoronary thermodilution allows an accurate and reproducible assessment of absolute coronary blood flow and microvascular resistance thus allowing the evaluation of coronary flow reserve (CFR) and Microvascular Resistance Reserve (MRR), a novel index specific for microvascular function, which is independent from the myocardial mass. In the present study we compared absolute coronary flow and resistance, CFR and MRR assessed by continuous intracoronary thermodilution in diabetic versus non-diabetic patients. Left atrial reservoir strain (LASr), an early marker of DDF was compared between the two groups.

Methods

In this observational retrospective study, 108 patients with suspected angina and non-obstructive coronary artery disease (NOCAD) consecutively undergoing elective coronary angiography (CAG) from September 2018 to June 2021 were enrolled. The invasive functional assessment of microvascular function was performed in the left anterior descending artery (LAD) with intracoronary continuous thermodilution. Patients were classified according to the presence of DM. Absolute resting and hyperemic coronary flow (in mL/min) and resistance (in WU) were compared between the two cohorts. FFR was measured to assess coronary epicardial lesions, while CFR and MRR were calculated to assess microvascular function. LAS, assessed by speckle tracking echocardiography, was used to detect early myocardial structural changes potentially associated with microvascular dysfunction.

Results

The median FFR value was 0.83 [0.79–0.87] without any significant difference between the two groups. Absolute resting and hyperemic flow in the left anterior descending coronary were similar between diabetic and non-diabetic patients. Similarly, resting and hyperemic resistances did not change significantly between the two groups. In the DM cohort the CFR and MRR were significantly lower compared to the control group (CFR=2.4±0.6 and 2.9±0.8; MRR=2.8±0.9 and 3.5±1 for diabetic and non-diabetic patients respectively, [p&lt;0.05 for both], Figure 1 and 2). Likewise, diabetic patients had a significantly lower reservoir, contractile and conductive LAS (all p&lt;0.05).

Conclusions

Compared with non-diabetic patients, CFR and MRR were lower in patients with DM and non-obstructive epicardial coronary arteries, while both resting and hyperemic coronary flow and resistance were similar. LASr was lower in diabetic patients, confirming the presence of a subclinical DDF associated to the microcirculatory impairment. Continuous intracoronary thermodilution-derived indexes provide a reliable and operator-independent assessment of coronary macro- and microvasculature and might potentially facilitate widespread clinical adoption of invasive physiologic assessment of suspected microvascular disease.

Funding Acknowledgement

Type of funding sources: None.

Deferral of Coronary Revascularization in Patients With Reduced Ejection Fraction Based on Physiological Assessment: Impact on Long-Term Survival

Background Deferring revascularization in patients with nonsignificant stenoses based on fractional flow reserve (FFR) is associated with favorable clinical outcomes up to 15 years. Whether this holds true in patients with reduced left ventricular ejection fraction is unclear. We aimed to investigate whether FFR provides adjunctive clinical benefit compared with coronary angiography in deferring revascularization of patients with intermediate coronary stenoses and reduced left ventricular ejection fraction. Methods and Results Consecutive patients with reduced left ventricular ejection fraction (≤50%) undergoing coronary angiography between 2002 and 2010 were screened. We included patients with at least 1 intermediate coronary stenosis (diameter stenosis ≥40%) in whom revascularization was deferred based either on angiography plus FFR (FFR guided) or angiography alone (angiography guided). The primary end point was the cumulative incidence of all-cause death at 10 years. The secondary end point (incidence of major adverse cardiovascular and cerebrovascular events) was a composite of all-cause death, myocardial infarction, any revascularization, and stroke. A total of 840 patients were included (206 in the FFR-guided group and 634 in the angiography-guided group). Median follow-up was 7 years (interquartile range, 3.22-11.08 years). After 1:1 propensity-score matching, baseline characteristics between the 2 groups were similar. All-cause death was significantly lower in the FFR-guided group compared with the angiography-guided group (94 [45.6%] versus 119 [57.8%]; hazard ratio [HR], 0.65 [95% CI, 0.49-0.85]; P<0.01). The rate of major adverse cardiovascular and cerebrovascular events was lower in the FFR-guided group (123 [59.7%] versus 139 [67.5%]; HR, 0.75 [95% CI, 0.59-0.95]; P=0.02). Conclusions In patients with reduced left ventricular ejection fraction, deferring revascularization of intermediate coronary stenoses based on FFR is associated with a lower incidence of death and major adverse cardiovascular and cerebrovascular events at 10 years.

First report of totally robotically assisted hybrid coronary artery revascularization combining RE-MIDCAB and R-PCI: Case report

A 62-year-old man presents to the Cardiology Department with a history of angina on exertion. Invasive coronary angiography revealed a severe three vessels coronary artery disease. The "Hybrid Heart Team" successfully performed a fully robotically assisted hybrid revascularization combining robotically enhanced-minimally invasive direct coronary artery bypass on the left anterior descending (LAD) and robotically assisted percutaneous coronary intervention on non-LAD lesions.

Contemporary Management of Stable Coronary Artery Disease

Coronary artery disease (CAD) continues to be the leading cause of mortality and morbidity in developed countries. Assessment of pre-test probability (PTP) based on patient's characteristics, gender and symptoms, help to identify more accurate patient's clinical likelihood of coronary artery disease. Consequently, non-invasive imaging tests are performed more appropriately to rule in or rule out CAD rather than invasive coronary angiography (ICA). Coronary computed tomography angiography (CCTA) is the first-line non-invasive imaging technique in patients with suspected CAD and could be used to plan and guide coronary intervention. Invasive coronary angiography remains the gold-standard method for the identification and characterization of coronary artery stenosis. However, it is recommended in patients where the imaging tests are non-conclusive, and the clinical likelihood is very high, remembering that in clinical practice, approximately 30 to 70% of patients with symptoms and/or signs of ischemia, referred to coronary angiography, have non obstructive coronary artery disease (INOCA). In this contest, physiology and imaging-guided revascularization represent the cornerstone of contemporary management of chronic coronary syndromes (CCS) patients allowing us to focus specifically on ischemia-inducing stenoses. Finally, we also discuss contemporary medical therapeutic approach for secondary prevention. The aim of this review is to provide an updated diagnostic and therapeutic approach for the management of patients with stable coronary artery disease.

451 Deferral of coronary revascularization in patients with reduced ejection fraction based on physiological assessment: impact on long-term survival

Aims

Deferring percutaneous coronary intervention (PCI) in patients with non-significant stenoses based on fractional flow reserve (FFR) is associated with favourable clinical outcomes up to 15 years. Whether this holds true in patients with reduced left ventricular ejection fraction (LVEF) is unclear. To investigate whether FFR provides adjunctive clinical benefit compared to coronary angiography in deferring revascularization of patients with intermediate coronary stenoses and reduced LVEF.

Methods and results

Consecutive patients (n = 4577) with reduced LVEF (≤50%) undergoing coronary angiography between 2002 and 2010 were screened. We eventually included patients with at least one intermediate coronary stenosis (diameter stenosis ≥40%) in whom revascularization was deferred based either on angiography plus FFR (FFR-guided) or angiography alone (angiography-guided). The primary endpoint of the study was the cumulative incidence of all-cause death at 10 years. The secondary endpoint [the incidence of major adverse cardiovascular and cerebrovascular events (MACCE)], was a composite of all-cause death, myocardial infarction, any revascularization and stroke. A total of 840 patients were included (206 in the FFR-guided and 634 in the angiography-guided group). Median clinical follow-up was 7 years [IQR: (3.22–11.08)]. After 1:1 propensity score matching, baseline characteristics between the two groups were similar. All-cause death was significantly lower in the FFR-guided group compared with the angiography-guided group [94 (45.6%) vs. 119 (57.8%), HR: 0.65 (95% CI: 0.49–0.85), P &lt; 0.01]. The rate of major adverse cardiovascular and cerebrovascular events [(MACCE), a composite of all-cause death, myocardial infarction, any revascularization, and stroke) was lower in the FFR-guided group [123 (59.7%) vs. 139 (67.5%), HR: 0.75 (95% CI: 0.59–0.95), P = 0.02].

Conclusions

In patients with reduced LVEF, deferring revascularization of intermediate coronary stenoses based on FFR is associated with a lower incidence of death and MACCE at 10 years.

Microvascular Dysfunction in Patients With Type II Diabetes Mellitus: Invasive Assessment of Absolute Coronary Blood Flow and Microvascular Resistance Reserve

Background: Coronary microvascular dysfunction (CMD) is an early feature of diabetic cardiomyopathy, which usually precedes the onset of diastolic and systolic dysfunction. Continuous intracoronary thermodilution allows an accurate and reproducible assessment of absolute coronary blood flow and microvascular resistance thus allowing the evaluation of coronary flow reserve (CFR) and Microvascular Resistance Reserve (MRR), a novel index specific for microvascular function, which is independent from the myocardial mass. In the present study we compared absolute coronary flow and resistance, CFR and MRR assessed by continuous intracoronary thermodilution in diabetic vs. non-diabetic patients. Left atrial reservoir strain (LASr), an early marker of diastolic dysfunction was compared between the two groups. Methods: In this observational retrospective study, 108 patients with suspected angina and non-obstructive coronary artery disease (NOCAD) consecutively undergoing elective coronary angiography (CAG) from September 2018 to June 2021 were enrolled. The invasive functional assessment of microvascular function was performed in the left anterior descending artery (LAD) with intracoronary continuous thermodilution. Patients were classified according to the presence of DM. Absolute resting and hyperemic coronary blood flow (in mL/min) and resistance (in WU) were compared between the two cohorts. FFR was measured to assess coronary epicardial lesions, while CFR and MRR were calculated to assess microvascular function. LAS, assessed by speckle tracking echocardiography, was used to detect early myocardial structural changes potentially associated with microvascular dysfunction. Results: The median FFR value was 0.83 [0.79-0.87] without any significant difference between the two groups. Absolute resting and hyperemic flow in the left anterior descending coronary were similar between diabetic and non-diabetic patients. Similarly, resting and hyperemic resistances did not change significantly between the two groups. In the DM cohort the CFR and MRR were significantly lower compared to the control group (CFR = 2.38 ± 0.61 and 2.88 ± 0.82; MRR = 2.79 ± 0.87 and 3.48 ± 1.02 for diabetic and non-diabetic patients respectively, [p < 0.05 for both]). Likewise, diabetic patients had a significantly lower reservoir, contractile and conductive LAS (all p < 0.05). Conclusions: Compared with non-diabetic patients, CFR and MRR were lower in patients with DM and non-obstructive epicardial coronary arteries, while both resting and hyperemic coronary flow and resistance were similar. LASr was lower in diabetic patients, confirming the presence of a subclinical diastolic dysfunction associated to the microcirculatory impairment. Continuous intracoronary thermodilution-derived indexes provide a reliable and operator-independent assessment of coronary macro- and microvasculature and might potentially facilitate widespread clinical adoption of invasive physiologic assessment of suspected microvascular disease.

Microvascular Resistance Reserve for Assessment of Coronary Microvascular Function: JACC Technology Corner

The need for a quantitative and operator-independent assessment of coronary microvascular function is increasingly recognized. We propose the theoretical framework of microvascular resistance reserve (MRR) as an index specific for the microvasculature, independent of autoregulation and myocardial mass, and based on operator-independent measurements of absolute values of coronary flow and pressure. In its general form, MRR equals coronary flow reserve (CFR) divided by fractional flow reserve (FFR) corrected for driving pressures. In 30 arteries, pressure, temperature, and flow velocity measurements were obtained simultaneously at baseline (BL), during infusion of saline at 10 mL/min (rest) and 20 mL/min (hyperemia). A strong correlation was found between continuous thermodilution-derived MRR and Doppler MRR (r = 0.88; 95% confidence interval: 0.72-0.93; P < 0.001). MRR was independent from the epicardial resistance, the lower the FFR value, the greater the difference between MRR and CFR. Therefore, MRR is proposed as a specific, quantitative, and operator-independent metric to quantify coronary microvascular dysfunction.

Importance of In-Hospital Prospective Registry and Infectious Endocarditis Heart Team to Monitor and Improve Quality of Care in Patients with Infectious Endocarditis

Aim: To investigate the value of prospective in-hospital registry data and the impact of an infectious endocarditis heart team approach (IEHT) on improvement in quality of care and monitor outcomes in hospitalized patients with IE. Methods: Between December 2014 and the end of 2019, 160 patients were hospitalized in one centre with the definite diagnosis of infectious endocarditis (IE) and entered in a prospective registry. From 2017, an IEHT was introduced. Propensity score matching was used to assess the impact of an IEHT approach on clinical outcomes. Results: Median age was 72.5 y (62.75–80.00), diabetes was present in 33.1%, chronic kidney disease in 27.5%, COPD in 17.5%, and a history of ischaemic heart disease in 30.6%. Prosthetic valve IE was observed in 43.8% and device-related IE in 16.9% of patients. Staphylococcus (37.5%) was the most frequent pathogen followed by streptococcus (24.4%) and enterococcus (23.1%). Overall, 30-day and 1-year mortality were 19.4% and 37.5%, respectively. The introduction of prospective data collection and IE heart team was associated with a trend towards reduction of adjusted 1-year mortality (26.5% IEHT vs. 41.2% controls, p = 0.0699). An IEHT clinical decision-making approach was independently associated with a shorter length of stay (p = 0.04). Conclusions: Use of a prospective registry of IE coupled with a heart team approach was associated with more efficient patient management and a trend towards lower mortality. Prospective data collection and dedicated IEHT have the potential to improve patient care and clinical outcomes.

Hyperemic hemodynamic characteristics of serial coronary lesions assessed by pullback pressure gradients

OBJECTIVES

To characterize hemodynamics of serial coronary stenoses using fractional flow reserve (FFR) pullbacks and the pullback pressure gradients (PPG) index.

BACKGROUND

The cross-talk between stenoses within the same coronary artery makes the prediction of the functional contribution of each lesion challenging.

METHODS AND RESULTS

One-hundred seventeen patients undergoing coronary angiography for stable angina were prospectively recruited. Serial lesions were defined as two or more narrowings with visual diameter stenosis >50% on conventional angiography. Motorized FFR pullback tracings were obtained at 1 mm/s. Pullbacks were visually adjudicated as presenting two, one, and no focal pressure drops. The pattern of disease (i.e., focal or diffuse) was quantified using the PPG index. Twenty-five vessels presented serial lesions (mean PPG 0.48 ± 0.17). Two, one or no focal pressure drops were observed in 40% (n = 10; PPG 0.59 ± 0.17), 52% (n = 13; PPG 0.44 ± 0.12) and 8% of cases (n = 2; PPG 0.27 ± 0.01; p-value = 0.01). Distal FFR was similar between vessels with two, one and no focal pressure drops in the pullback curve (p-value = 0.27). The PPG index independently predicted the presence of two focal pressure drops in the pullback curve (p = 0.04).

CONCLUSIONS

FFR pullbacks in serial coronary lesions exhibit three distinct functional patterns. High PPG was associated with pullback curves presenting two pressure drops. The PPG provides a quantitative assessment of the pattern of coronary artery disease in cases with serial lesions and might be useful to assess the appropriateness of percutaneous revascularization.

Procedural microvascular activation in long lesions treated with bioresorbable vascular scaffolds or everolimus-eluting stents: the PROACTIVE trial

AIMS

Significant platelet activation after long stented coronary segments has been associated with periprocedural microvascular impairment and myonecrosis. In long lesions treated either with an everolimus-eluting bioresorbable vascular scaffold (BVS) or an everolimus-eluting stent (EES), we aimed to investigate (a) procedure-related microvascular impairment, and (b) the relationship of platelet activation with microvascular function and related myonecrosis.

METHODS AND RESULTS

Patients (n=66) undergoing elective percutaneous coronary intervention (PCI) in long lesions were randomised 1:1 to either BVS or EES. The primary endpoint was the difference between groups in changes of pressure-derived corrected index of microvascular resistance (cIMR) after PCI. Periprocedural myonecrosis was assessed by high-sensitivity cardiac troponin T (hs-cTnT), platelet reactivity by high-sensitivity adenosine diphosphate (hs-ADP)-induced platelet reactivity with the Multiplate Analyzer. Post-dilatation was more frequent in the BVS group, with consequent longer procedure time. A significant difference was observed between the two groups in the primary endpoint of ΔcIMR (p=0.04). hs-ADP was not different between the groups at different time points. hs-cTnT significantly increased after PCI, without difference between the groups.

CONCLUSIONS

In long lesions, BVS implantation is associated with significant acute reduction in IMR as compared with EES, with no significant interaction with platelet reactivity or periprocedural myonecrosis.

3286Fractional flow reserve-guided treatment strategy for left main coronary artery stenoses. Ten-year clinical outcome

Background

Revascularization decisions regarding left main (LM) coronary stenoses are often very challenging. Non-invasive tests can yield false negative results. On the other hand, some technical aspects of fractional flow reserve (FFR) measurement, as well as the interpretation of their results, are less codified than for other coronary segments.

Purpose

To investigate the 10-year clinical outcome of patients with isolated angiographically intermediate LM coronary stenosis in whom the treatment strategy was based on Fractional Flow Reserve (FFR) measurements.

Methods

From 1999 to 2009 we included 96 patients with isolated intermediate LM coronary disease (DS% 30–70%) evaluated with FFR measurement. When FFR was >0.80, patients were deferred to medical therapy (Deferral-group, n=71). When FFR was ≤0.8, surgical revascularization therapy was proposed (Revascularization-group, n=25). Death, the occurrence of myocardial infarction (MI) and the need for target vessel revascularization (TVR) were evaluated in both groups.

Results

There were no significant differences in clinical characteristics between the 2 groups. Mean DS% was 35% in the Deferral-group and 43% in the Revascularization-group (p<0.01). Average FFR was 0.88 in the Deferral-group and 0.71 in the Revascularization-group (p<0.01). In the latter, the 10-year survival estimate was 72% while it was 77% in the Deferral group (HR [95% CI]: 1.28 [0.53–3.10]; p=NS). No difference was found between the 2 groups in terms of MI (4.5% vs. 1.6%; HR [95% CI]: 3.5 [0.22–56.0]; p=NS) or TVR (9% vs. 12%; HR [95% CI]: 0.94 [0.20–4.43]; p=NS).

Conclusions

The use of FFR to defer revascularization in patients with non-significant isolated LM stenosis is safe and is associated with favourable clinical outcome at 10 years.

Intracoronary EnalaPrilat to Reduce MICROvascular Damage During Percutaneous Coronary Intervention (ProMicro) study

OBJECTIVES

This study investigated the influence of intracoronary enalaprilat on coronary microvascular function and peri-procedural outcome measures in patients with stable angina undergoing percutaneous coronary intervention (PCI).

BACKGROUND

Intracoronary angiotensin-converting enzyme inhibitors have been shown to relieve myocardial ischemia in stable patients and to improve epicardial flow in patients with ST-segment elevation myocardial infarction. Yet, it is still unclear whether these effects are mediated by a modulation of the coronary microcirculation.

METHODS

We randomly assigned 40 patients to receive either an intracoronary bolus of enalaprilat (50 μg) or placebo before elective PCI. The index of microvascular resistance was measured at baseline, 10 minutes after study drug administration, and after PCI. High-sensitivity cardiac troponin T was measured as a marker of myocardial injury.

RESULTS

Infusion of enalaprilat resulted in a significant reduction in index of microvascular resistance (27 ± 11 at baseline vs. 19 ± 9 after drug vs. 15 ± 8 after PCI), whereas a significant post-procedural increase in index of microvascular resistance levels was observed in the placebo group (24 ± 15 at baseline vs. 24 ± 15 after drug vs. 33 ± 19 after PCI). Index of microvascular resistance levels after PCI were significantly lower in the enalaprilat group (p < 0.001). Patients pre-treated with enalaprilat also showed lower peak values (mean: 21.7 ng/ml, range: 8.2 to 34.8 ng/ml vs. mean: 32.3 ng/ml, range: 12.6 to 65.2 ng/ml, p = 0.048) and peri-procedural increases of high-sensitivity cardiac troponin T (mean: 9.9 ng/ml, range: 2.7 to 19.0 ng/ml vs. mean: 26.6 ng/ml, range: 6.3 to 60.5 ng/ml, p = 0.025).

CONCLUSIONS

Intracoronary enalaprilat improves coronary microvascular function and protects myocardium from procedure-related injury in patients with coronary artery disease undergoing PCI. Larger studies are warranted to investigate whether these effects of enalaprilat could result into a significant clinical benefit.

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.

Fractional flow reserve and myocardial perfusion imaging in patients with angiographic multivessel coronary artery disease

OBJECTIVES

The aim of this study was to investigate the correlation between myocardial ischemia detected by myocardial perfusion imaging (MPI) with single-photon emission computed tomography with intracoronary pressure-derived fractional flow reserve (FFR) in patients with multivessel coronary disease at angiography.

BACKGROUND

Myocardial perfusion imaging can underestimate the number of ischemic territories in patients with multivessel disease. However, there are limited data comparing MPI and FFR, a highly accurate functional index of myocardial ischemia, in multivessel coronary disease.

METHODS

Sixty-seven patients (201 vascular territories) with angiographic 2- or 3-vessel coronary disease were prospectively scheduled to undergo within 2 weeks MPI (rest/stress adenosine) and FFR in each vessel.

RESULTS

In 42% of patients, MPI and FFR detected identical ischemic territories (mean number of territories 0.9 +/- 0.8 for both; p = 1.00). In the remaining 36% MPI underestimated (mean number of territories; MPI: 0.46 +/- 0.6, FFR: 2.0 +/- 0.6; p < 0.001) and in 22% overestimated (mean number of territories; MPI: 1.9 +/- 0.8, FFR: 0.5 +/- 0.8; p < 0.001) the number of ischemic territories in comparison with FFR. There was poor concordance between the ability of the 2 methods to detect myocardial ischemia on both a per-patient (kappa = 0.14 [95% confidence interval: -0.10 to 0.39]) and per-vessel (kappa = 0.28 [95% confidence interval: 0.15 to 0.42]) basis.

CONCLUSIONS

Myocardial perfusion imaging with single-photon emission computed tomography has poor concordance with FFR and tends to underestimate or overestimate the functional importance of coronary stenosis seen at angiography in comparison with FFR in patients with multivessel disease. These findings might have important consequences in using MPI to determine the optimal revascularization strategy in patients with multivessel coronary disease.

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.

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.

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.

Relation of low response to clopidogrel assessed with point-of-care assay to periprocedural myonecrosis in patients undergoing elective coronary stenting for stable angina pectoris

Impaired responses to antiplatelet therapy assessed by laboratory tests are associated with an increased risk of recurrent ischemic events after percutaneous coronary intervention (PCI). This study was designed to determine the relation between responses to aspirin and clopidogrel as assessed by a point-of-care assay (Verify Now, Accumetrics, San Diego, California) and periprocedural myocardial infarction (PMI) in patients undergoing elective PCI for stable angina. One hundred twenty-two consecutive patients undergoing elective coronary stenting prospectively received aspirin 500 mg and clopidogrel 600 mg >or=12 hours before PCI. Clopidogrel response was measured with P2Y12 reaction units (PRUs) and percent inhibition P2Y12 from baseline (percent inhibition P2Y12) and aspirin response with aspirin reaction units (ARUs). Troponin T level was considered positive if it was >0.03 ng/ml. Responses to aspirin and clopidogrel were correlated (r=0.42, p <0.0001). PMI occurred in 27 patients (22%) who showed significantly lower percent inhibition P2Y12 (25.3+/-26 vs 38.3+/-25, p=0.01) and a trend toward higher PRU values (221+/-87 vs 193+/-94, p=0.21). We did not find any difference for aspirin response as assessed by ARUs in patients with or without PMI (460+/-82 vs 454+/-73, p = 0.82). Stratification of percent inhibition P2Y12 isolated a quartile of clopidogrel nonresponders (inhibition P2Y12 <15%) with significantly higher incidence of PMI (44% vs 15%, odds ratio 4.6, 95% confidence interval 1.9 to 11.5, p=0.001). In conclusion, point-of-care assessment of clopidogrel response reliably predicted PMI after low- to medium-risk elective PCI for stable angina.

Effects of intravenous dobutamine on coronary vasomotion in humans

OBJECTIVES

We sought to investigate the vascular mechanisms of dobutamine-induced myocardial ischemia.

BACKGROUND

Dobutamine stress is often used as a surrogate for exercise. The effects of dobutamine on the epicardial arteries are incompletely understood and possibly different from those of physical exercise.

METHODS

Intravenous (IV) dobutamine (40 microg/kg per min) was administered in 19 patients with normal, 23 patients with mildly atherosclerotic, and 12 patients with stenotic coronary arteries. In another two groups of patients with stenotic arteries, IV dobutamine was preceded by 1) an intracoronary (IC) bolus of the alpha-adrenergic blocker phentolamine (12 microg/kg, n = 12); and 2) an IC infusion of the nitric oxide substrate L-arginine (150 micromol/l per min for 20 min, n = 11). Intravenous saline instead of dobutamine was infused into eight patients with normal arteries. After dobutamine (or saline), an IC bolus of isosorbide dinitrate (ISDN, 0.2 mg) was given. Coronary vasomotion was evaluated by quantitative coronary angiography on angiograms obtained after each dose of dobutamine, saline, phentolamine, L-arginine, and ISDN.

RESULTS

Dobutamine increased the rate-pressure product and heart rate similarly in all patients except those who received saline. Dobutamine induced vasodilation in normal (change in luminal diameter [DeltaLD] vs. baseline: 19 +/- 2%) and in mildly atherosclerotic arteries (DeltaLD: 8 +/- 2%, p < 0.05 vs. normal). In stenotic arteries, dobutamine did not induce significant vasomotion (DeltaLD: -3 +/- 3%); the latter was improved by L-arginine (DeltaLD: 10 +/- 3%, p < 0.05 vs. stenotic arteries) and fully restored by phentolamine (DeltaLD: 19 +/- 3%, p < 0.05 vs. stenotic arteries).

CONCLUSIONS

Endothelial dysfunction and enhanced alpha-adrenergic tone contribute to the loss of dobutamine-induced vasodilation in coronary atherosclerosis. In contrast to physical exercise, dobutamine does not induce "paradoxical vasoconstriction" of atherosclerotic coronary arteries.