Additive negative prognostic value of coronary flow reserve in patients with left bundle branch block without inducible ischemia and without known coronary artery disease

Background

Left bundle branch block (LBBB) can be isolated thing, but it is also often associated with underlying coronary artery disease (CAD). Stress echocardiography (SECHO) is widely used as an imaging method for the diagnosis of CAD. However, the diagnostic value of stress echocardiography in patients (pts) with LBBB is limited.

Purpose

To evaluate negative prognostic value of coronary flow reserve (CFR) in pts with LBBB without inducible ischemia and without known CAD.

Methods

This retrospective study included 224 pts (98, 43.8% male gender, average age 66±11 years) with LBBB and without known CAD. All the pts had negative SECHO test according the Bruce protocol. Risk factors for CAD (diabetes, smoking, hypertension, high cholesterol and positive family history of CAD), Duke treadmill score, functional capacity (Metabolic Equivalents - METs) were recorded in all pts. Out of 224 pts, in 64 (29.5%) coronary flow reserve on the left anterior descending artery was assessed using pulsed Doppler echocardiography with adenosine in a dose of 140μcg/kg/body weight during 3 minutes. As the normal value we took value of CFR ≥2. Median follow up of the pts was 72 months (IQR 56.25–132 months) for the occurrence of MACE (cardiovascular death (CVD), non-fatal myocardial infarction (nfMI), coronary artery bypass graft (CABG) and percutaneous coronary revascularization (PCI).

Results

Out of 224 pts, 6 (2.7%) had positive SECHO test, 2 pts (0.9%) had died due to non-cardiac causes and 11 pts (4.9%) were lost to follow up so they were excluded from further analysis. The remaining 204 pts were divided in 2 groups: 1. pts with only negative SECHO (n=144, 68.8%); 2. pts with negative SECHO and normal CFR (n=64, 31.2%). During the follow-up period 22 out of 205 pts (10.7%) had an adverse event (6 CVD, 6 nfMI, 5 CABG, 8 PCI). Between the two groups there was no significant difference in risk factors and parameters of the SECHO test. Pts with CFR had significantly lower rate of MACE compared to the pts with only SECHO test (2, 3.1% vs 20, 14.2%, p=0.018, respectively). Using the Cox regression analysis, univariate predictors of MACE were insulin dependent diabetes (HR 10.851 [95% CI 2.095–56.220], p=0.004), Duke score (HR 0.603 [95% CI 0.414–0.878], p=0.008), and MET (HR 0.393 [95% CI 0.209–0.737], p=0.004). In the multivariate analysis only the insulin dependent diabetes remained an independent predictor of MACE (HR 6.906 [95% CI 1.100–43.363], p=0.039). Using the Kaplan-Meier survival curve we see that the pts with SECHO test and CFR had shorter event-free time compared to the pts with SECHO test (136.3±3.6 months vs 149.8±2.9 months, Log Rank 4.022, p=0.045) (Figure 1).

Conclusion

Normal value of CFR has good negative prognostic value in pts with LBBB without inducible ischemia and without known CAD, while pts with insulin dependent diabetes have more pronounced risk for the occurrence of adverse events.

Funding Acknowledgement

Type of funding sources: None.

Haemodynamic indicators of arteriolar dysregulation during combined hyperventilation and exercise test in patients with ANOCA (SESPASM)

Introduction

In patients with angina and non-obstructed coronary arteries (ANOCA), functional dysregulation such as epicardial coronary spasm and microvascular dysfunction (microvascular spasm and /or impaired microvascular dilatation) frequently coexist.

The aim was to analyse haemodynamic indicators of arteriolar dysregulation during combined hyperventilation and exercise stress echo test in patients with ANOCA.

Methods

In a prospective study we enrolled 38 patients (56±13 years, 31 females) with ANOCA, proven by normal coronary angiogram. Stress echocardiography protocol with Doppler measurements of coronary flow consisted of hyperventilation test for spasm provocation (HYP, respiratory rate of 30 per min for 5') followed by supine bicycle exercise test (HYP+EXE) for assessment of endothelium dependent function. Adenosine test was done (ADO 140 mcg/kg in 1 min) for estimation of endothelium independent vasodilatation. Coronary flow velocity (CFV) was assessed in distal LAD by Transthoracic Doppler echocardiography at the end of the each stage of the test. Abnormal response to HYP was a CFV ratio (stress/rest) <1.0 (vasoconstrictor response). CFV ratio at peak HYP+ EXE was an indicator of endothelial dependent vasodilatation (<2 blunted response). An abnormal response to ADO was a CFV reserve <2.0 (blunted vasodilatory response).

Results

The double product increased during HYP in comparison to rest (13263 vs 10321, p<0.001), and further increased with EXE (23817 vs HYP, p<0.001). Chest pain was present in 6 pts during HYP, and in additional three pts during HYP+EXE (15.8% vs 23.7%, p=0.25). ST segment depression was present in 6 pts during HYP and 23 during HYP+EXE (15.79% vs 60.52%, p<0.001). Wall motion abnormality was provoked with HYP in three pts (7.89%) and in ten (26.3%) with HYP+EXE (p=0.016). CFV ratio was abnormal for vasoconstriction during HYP in 16 (42.1%) and blunted in 23 (60.52%) pts during HYP+EXE (Fig 1). Vasodilation during ADO was preserved in all patients, but one. There was significant difference between CFV reserve during HYP+EXE vs ADO (1.98±0.49 vs 2.53±0.43 respectively, p<0.001) (Fig. 2).

Conclusion

Our results indicate that HYP induce microvascular dysfunction with vasospastic component which is reflected in reduced CFV ratio. This prevents the normal hyperemic response during EXE in more than a half of patients. Endothelial independent vasodilatation during ADO hyperemia was perserved in all patients, excluding structural microvasculature remodeling. HYP+EXE provocation with noninvasive measurement of coronary flow is a promising test for assessing mechanism of arteriolar dysregulation in ANOCA patients.

Funding Acknowledgement

Type of funding sources: None.

Diagnostic accuracy of instantaneous wave-free ratio at rest and during dobutamine provocation to assess myocardial bridging relevance

Background

Diastolic fractional flow reserve (d-FFR) during dobutamine provocation (DOB) was found to be a more reliable physiological index for the functional assessment of myocardial bridging (MB). However, d-FFR calculation is complicated and time-consuming, and therefore several authors have suggested the use of instantaneous wave-free ratio (iFR) to overcome these issues.

Purpose

The aim of our study was to assess diagnostic performance of d-FFR and iFR at rest and during DOB with exercise-induced myocardial ischemia as reference.

Methods

Twenty-four symptomatic patients (17 males, mean age 58±8 years) with MB and systolic compression ≥50% diameter stenosis on the left anterior descending (LAD) artery were included. Exercise stress-echocardiography test (SE), and both d-FFR and iFR in the distal segment of LAD at rest and peak DOB (30–50μg/kg/min), were performed in all patients. Optimal cut-off values and diagnostic performance of resting and hyperemic d-FFR and iFR were assessed using SE.

Results

Exercise-SE was positive for myocardial ischemia in 7/24 patients (29%). The area-under-the-receiver-operating-characteristic curve (ROC-AUC) for exercise-induced myocardial ischemia was 0.64 (95% CI: 0.400–0.885) for resting d-FFR, 0.62 (95% CI: 0.378–0.866) for resting iFR, 1.000 (95% CI: 0.999–1.000) for d-FFR at peak DOB, and 0.96 (95% CI: 0.895–1.000) for iFR at peak DOB. No significant difference in ROC-AUC was observed between d-FFR and iFR at peak DOB (p=0.243). The best cut-off value for both d-FFR and iFR at peak DOB was <0.76 with similar sensitivity and negative predictive values (100 vs. 100% for both), but lower specificity and positive predictive value for iFR in identifying MB associated with exercise-induced ischemia (94% vs. 82%; 88% vs. 70%, respectively). Compared with exercise-induced myocardial ischemia, the diagnostic accuracy of d-FFR and iFR at peak DOB was 96% (kappa=0.903, p<0.001) and 88% (kappa=0.731, p<0.001), respectively.

Conclusions

iFR during DOB provocation showed similar diagnostic accuracy as d-FFR to identify the functionally significant MB when compared with exercise-induced myocardial ischemia.

Funding Acknowledgement

Type of funding sources: None.

Comparison of SCORE and SCORE 2 risk prediction tools in contemporary very high risk european population

Background

New SCORE 2 algorithm overperformed SCORE algorithm in population with decreasing prevalence of cardiovascular (CV) morbidity and mortality. However, there is limited data in risk stratification with SCORE 2 model in contemporary populations from very high risk countries.

Aim

The aim of this study was to compare risk prediction using SCORE 2 and SCORE model and to compare the proportions of patients requiring statin treatment in primary prevention.

Methods

Our study included 1317 patients (511, 38.8% male gender, average age 54±8) without known CV disease aged 40 to 70 years. Data on CV risk factors were prospectively collected in 20 primary care centers throughout the Serbia from January 2020. to December 2020. Based on the CV risk profile, patients were stratified into 4 categories: low, moderate, high and very high risk according to SCORE model and into 3 categories: low to moderate, high and very high risk according to SCORE 2 model. The number of patients requiring statin treatment was assessed according to the risk category and value of LDL cholesterol in SCORE model and the value of non-HDL cholesterol in SCORE 2 model.

Results

Overall, 589 patients (44.7%) were smokers, mean value of total cholesterol was 6.2±1.1 mmol/L, LDL 3.9±1.1, HDL 1.4±0.5, non HDL 4.8±1.2 mmol/L. Systolic blood pressure was 138.6±19.6, diastolic blood pressure was 85.3±10.4 mmHg and was BMI 26.9±5.2. Based on the SCORE model 166 patients (12.6%) were classified into low risk category, 658 (49.9%) into moderate, 276 (20.9%) into high risk and 217 (16.6%) into very high risk category. Based on the SCORE 2 model 30 (2.8%) patients were classified into low to moderate, 273 (18%) and 1014 (79.2%) into very high risk category. There was significantly less patients in low to moderate group in SCORE 2 model compared to SCORE model (30, 2.8% vs 824, 62.6%, p<0.001 respectively) and significantly more patients with very high risk (1014, 79.2% vs 217, 16.6%, p<0.001), but without significance difference in the high risk group (Figure 1). The use of SCORE 2 model resulted in significantly higher proportion of patients requiring statin treatment 93% vs. 43% using SCORE model (p<0.001).

Conclusion

The use SCORE 2 risk prediction tool, in comparison to SCORE model, results in significant higher proportion of patients being classified as very high risk category with the increase number of patients requiring statin treatment in primary prevention.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Krka Farma

Assessment of left ventricular contractile reserve during hyperventilation and exercise in patients with ANOCA

Funding Acknowledgements

Type of funding sources: None.

Introduction. Mechanism of ischemia in patients with angina and no obstructive coronary artery disease (ANOCA), is often unrecognized since invasive tests are seldom done and proper noninvasive test is not established yet.

The aim of our study was to assess changes in ventricular function during hyperventilation test  (HYP) designed to provoke vasoconstriction, immediately followed by supine bicycle exercise to increase ischemic stimuli in patients with ANOCA (HYP + EXE).

Methods. : In a prospective study, we enrolled 29 ANOCA patients  (age 59.6 ±11 years, 27 females) with previously normal angiograms. All patients underwent SE testing with hyperventilation (HYP, respiratory rate of 30 per min for 5"), immediately followed by supine bicycle exercise (HYP + EXE). Ventricular function was assessed based on left ventricular contractile reserve (LVCR), calculated by ratio of the ventricular force at the peak of the each stress level and rest. Force was assessed as the quotient between systolic arterial pressure and end-systolic volume determined by two-dimensional echocardiography. Values range from normal (> 2.0) to mild (1.5–2.0), moderate (1.01–1.49), and severe (≤1.0) dysfunction. For LVCR HYP values are shifted towards lower values (abnormal < 1.1).

Results. Chest pain or dyspnea were present in 4/29 pts during HYP, and in 7/29 patients during HYP + EXE (13.8% vs 24.1 %, p = 0.001). Three patients showed wall motion abnormalities with hyperventilation and additional two patients with HYP + EXE. LVCR HYP response was normal in 19/29 (65.5%) pts and abnormal in 10/29 (34.5%) pts. LVCR HYP + EXE response was normal in 9/29 (31%) pts, 4/29 (13.8%) pts had mild, 11/29 (37.9%) pts had moderate and 5/29 (17.3%) pts had severe dysfunction.

Conclusion. In patients with ANOCA subtle changes in LV function occurred with HYP and EXE stress more often than wall motion abnormality. Measurement of contractile reserve might be a useful tool in assessment of ischemia and ventricular dysfunction in patients with ANOCA. Abstract Figure 1.  Abstract Figure 2.

Cut-off value of coronary flow velocity reserve obtained by transthoracic Doppler echocardiography during intravenous infusion of dobutamine for diagnosis of functional significant myocardial bridging

Background

Recent studies showed that coronary flow velocity reserve (CFVR) measurement by transthoracic Doppler echocardiography (TTDE) during inotropic stimulation with dobutamine (DOB), in comparison to vasodilation with adenosine, provides more reliable functional evaluation of myocardial bridging (MB). However, the adequate cut-off value of CFVR during DOB for diagnosing functional significant MB has not been fully established.

Purpose

The purpose of the study was to evaluate the adequate cut-off value of TTDE- CFVR during DOB for diagnosis of functional significant MB.

Methods

This prospective study included 79 patients (54 males, mean age 55±10 years) with angiographic evidence of isolated MB on the left anterior descending artery (LAD) and systolic compression ≥50% diameter stenosis. Exercise stress-echocardiography test (ExSE) and TTDE-CFVR in the distal segment of LAD during DOB infusion (DOB: 10–40μg/kg/min) were performed in all patients. Percent diameter stenosis (DS) of MB at end-systole and end-diastole were analyzed using quantitative coronary angiography.

Results

Exercise-SE was positive for myocardial ischemia in 22/79 (28%). CFVR during peak DOB was significantly lower in SE-positive group in comparison to SE-negative group (1.94±0.16 vs. 2.78±0.53, p<0.001). ROC analysis identifies the optimal CFVR during peak DOB cut-off value <2.1 (AUC 0.985, 95% CI: 0.965–1.000, p<0.001), with a sensitivity of 96% and specificity of 95%, positive predictive value of 88%, and negative predictive value of 98%, for identifying functionally significant MB associated with stress-induced myocardial ischemia. The categorical agreement between TTDE-CFVR at peak DOB and ExSE was high (kappa value = 0.877, p<0.001). Multivariate logistic regression analysis showed that percent DS at end-diastole was the only independent predictor of ischemic CFVR value <2.1 (OR: 1.136, 95% CI: 1.045–1.235, p=0.003).

Conclusion

A cut-off value <2.1 of CFVR during DOB infusion obtained by TTDE may adequate discriminate functional significant MB that induce myocardial ischemia which is caused by an incomplete diastolic MB-decompression.

Funding Acknowledgement

Type of funding sources: None.

Noninvasive functional testing in ANOCA: hyperventilation-exercise study for spasm (SESPASM)

Introduction

In patients with angina and no obstructive coronary artery disease (ANOCA), different mechanisms of ischaemia, epicardial spasm, microvascular spasm, and impaired microvascular dilatation frequently coexist.

The aim was to assess CFVR changes during coronary vasoconstrictor and vasodilator stimuli in patients with ANOCA.

Methods

In a prospective single center study, we enrolled 29 ANOCA patients (age 59.6±11 years, 27 females) with previously normal angiograms. All underwent SE testing with hyperventilation (HYP, respiratory rate of 30 per min for 5') followed by supine bicycle exercise (HYP+EXE); and adenosine CFV evaluation (ADO 140 mcg/kg in 1 min) on the other day. Coronary flow velocity (CFV) was assessed in distal LAD by Transthoracic Doppler echocardiography. The ratio of peak/rest changes of CFV during HYP in LAD was taken as an index of vasoconstriction, and CFV reserve was evaluated after EXE. An abnormal response to HYP was a CFV ratio <1.0 (vasoconstrictor response). An abnormal response to ADO was a CFV reserve <2.0 (blunted vasodilatory response). CFVR at peak HYP+ EXE was an indicator of endothelial dependent vasodilatation.

Results

The double product increased during HYP, in comparison to rest (13213 vs 10517, p<0.01), and further increased with EXE (23387 vs HYP, p<0.001). Chest pain or dyspnea were present in 4/29 pts during HYP, and in 7/29 patients during HYP+EXE (13.8% vs 24.1%, p=0.001). ST segment depression (≥1mm) was present in 7/29 patients during HYP, and 14/29 during HYP+EXE (24.13% vs 48.3%, p<0.01). Five patients (17%) showed regional wall motion abnormalities with HYP+EXE. CFVR response was abnormal in 19/29 (65%) patients during HYP+EXE, and abnormal for vasoconstriction during HYP in 13 (44%). Vasodilation during ADO was preserved in all patients.There was significant difference between CFVR response during HYP+EXE and ADO (1.9±0.35 vs 2.47±0.42 respectively, p<0.01), and between CFVR HYP and ADO (1.28±0.29 vs 2.47±0.42, p<0.001).

Conclusion

In patients with ANOCA, HYP+EXE is a more powerful ischemic stress than HYP alone. In over one-half of patients HYP+EXE unmasks abnormalities in CFVR response and/or regional wall motion, likely unmasking the underlying endothelium dependent microcirculatory dysfunction with enhanced vasoconstriction in 44% of the patients and mixed vasoconstriction and reduced relaxation in 65%.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): University Clinical Centre of Serbia, Faculty of Medicine

Prognostic value of mitral regurgitation in patients with asymmetric hypertrophic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Introduction

Since mitral regurgitation (MR) is a very common finding in patients with hypertrophic cardiomyopathy (HCM), the evaluation of the mitral valve anatomy and the degree of MR is of utmost importance in this population. However, data regarding the prognostic value of different degrees of MR in HCM remains scarce.

Purpose

The aim of this study was to determine whether the presence of a higher degree of MR affects: 1) long term prognosis; 2) clinical and echocardiographic presentation of HCM patients.

Material and Methods

We included prospectively 102 patients, diagnosed with primary asymmetric HCM. The degree of MR was determined echocardiographicaly according to current recommendations of the American Association of Echocardiography. According to the MR severity, patients were divided into 2 groups: Group 1 (n = 52) with no/trace or mild MR and Group 2 with moderate or moderate to severe MR. All patients had clinical and echocardiographic examination, 24-hour Holter ECG and NT pro BNP analysis performed. The primary outcome was a composite of: 1) HCM related death or sudden death; 2) hospitalization due to acute heart failure; 3) sustained ventricular tachycardia; 4) ischemic stroke.

Results

Patients with higher MR degree had more frequent chest pain (p = 0.039), syncope (p = 0.041) and NYHA II functional class (p < 0.001). Group 2 patients had mostly obstructive form of HCM (p < 0.001) with more frequent presence of previous atrial fibrillation (AF) (p = 0.032), as well as the new onset of AF (p = 0.014) compared to patients in Group 1. Patients with higher MR degree had significantly more SAM (p < 0.001) resulting in a more frequent eccentric MR jet (p < 0.001), along with calcified mitral annulus (p = 0.007), enlarged left atrial volume index (p < 0.001), and elevated right ventricular pressure (p = 0.001). As a result of higher MR grade, Group 2 had higher E/e" values (p < 0.001), elevated LV filling pressure (lateral E/e’ >10), as well as higher levels of NT pro BNP (p = 0.001). By Kaplan-Meier analysis we demonstrated that the event free survival rate during follow up of median 75 (IQR 48-103) months was significantly higher in Group 1 compared to the Group 2 (79% vs. 46%, p < 0.001), Figure 1. After adjustment for relevant confounders, moderate/moderate to severe MR remained as an independent predictor of adverse outcome (hazard ratio 2.58, 95% CI: 1.08-6.13, p < 0.001).

Conclusion

Presence of moderate, or moderate to severe MR was associated with poor long-term outcome of HCM patients. These results indicate the importance of an adequate MR assessment and detailed evaluation of the mitral valve anatomy in the prediction of complications and adequate treatment of patients with HCM.

Abstract Figure.

Long term perspective with LBBB: role of stress echocardiography

Background

Previous studies have shown that left bundle branch block (LBBB), as a relatively common electrocardiographic (ECG) abnormality, represents the condition with often non benign and sometimes adverse outcome.

Purpose

The Aim of our study was to determine the predictive value of a stress echocardiography test in patients with LBBB.

Methods

Our study population included 189 patients (88 male, 46.6%, mean age 63.08±9.65) with diagnosed left bundle branch block who performed stress echocardiography (SECHO) according to Bruce protocol. Median follow-up of the patients was 56 months (IQR 48–71 months) for the occurrence of cardiovascular death and non-fatal myocardial infarction, repeat revascularization (coronary artery bypass grafting-CABG or percutaneous coronary intervention-PCI).

Results

Out of 189 patients, 32 (16.9%) patients had positive, while 157 (83.1%) patients had negative SECHO test. During the follow up period 28 patients had major adverse cardiac event: 1 nonfatal myocardial infarction, 6 heart failure hospitalizations, 5 CABGs, 8 PCIs, while 8 patients had cardiac death. Using the Cox regression analysis, univariate predictors of adverse cardiac events were diabetes mellitus (HR 4.530 [95% CI 1.355–15.141], p=0.014), PCI (HR 4.288 [95% [95% CI 2.010–9.144], p<0.001) and positive SECHO test (HR 2.289 [95% CI 1.006–5207], p=0.048). In the multivariate analysis only previous PCI remained independent predictor of adverse events (HR 3.650 [95% CI 1.665–8.003], p=0.001). p=0.048). Using the Kaplan-Meier survival curve the patients with negative SECHO had better outcome compared to patients with positive SECHO (140/160; 87,5% vs 21/29; 72.4%, p=0.035) and much longer event-free time (77.4±1.6 months vs 67.1±5.4 months, Log Rank 4.136, p=0.042)

Conclusion

Patients with LBBB and negative SEHO test have good prognosis. Patients with history of CAD and diabetes mellitus and LBBB are at increased risk for future events and need periodical reassessment.

Funding Acknowledgement

Type of funding source: None

Time-dependent improvement in coronary flow reserve in collateral donor artery following successful recanalization of the Coronary Chronic Total Occlusion

Background

Coronary chronic total occlusion (CTO) is characterized by the presence of collateral blood vessels which can provide additional blood supply to CTO-artery dependent myocardium. Successful CTO recanalization is followed by significant decrease in collateral donor artery blood flow and collateral derecruitment.

Purpose

Study aim was to assess time-dependent changes in coronary flow reserve (CFR) in collateral donor artery after CTO recanalization and identify factors that influence these changes.

Methods

Our study enrolled 31 patients with CTO scheduled for percutaneous coronary intervention (PCI). Non-invasive CFR was measured before PCI in collateral donor artery, and 24h and 6 months post-PCI in CTO and collateral donor artery. Gated SPECT MIBI was performed before PCI, while quality of life was assessed by Seattle angina questionnaire (SAQ) pre-PCI, and 6 months after PCI.

Results

Collateral donor artery showed significant increase in CFR 24h after CTO recanalization compared to pre-PCI values (2.30±0.49 vs. 2.71±0.45, p=0.005), which remained unchanged after 6 months (2.68±0.24). Maximum baseline blood flow velocity of the collateral donor artery showed significant decrease measured 24h post-PCI compared to pre-PCI values (0.28±0.06 vs. 0.24±0.04m/s), and remained similar after 6-months. There was no significant difference in maximum hyperemic blood flow velocity pre-PCI, 24h and 6 months post-PCI. CFR change of the collateral donor artery 24h post-PCI compared to pre-PCI values showed inverse correlation with left ventricle ejection fraction (LVEF) measured on SPECT. CFR changes showed no correlation with the changes in quality of life assessed by SAQ post-PCI compared to pre-PCI.

Conclusions

Significant increase in CFR of the collateral donor artery was observed within 24h after successful recanalization of CTO artery, which maintained constant after the 6 months follow-up. This increase was largely driven by the significant reduction in the maximum baseline blood flow velocity within 24h after CTO recanalization compared to pre-PCI values. Our results suggest that possible benefit of CTO recanalization could be the improvement in physiology of the collateral donor artery.

Funding Acknowledgement

Type of funding source: None

Hyperventilation echocardiography in INOCA: the HEROIC study

Background

Patients with ischemia and no obstructive coronary artery disease (INOCA) are a heterogeneous group and an unmet diagnostic challenge. Noninvasive Doppler is a feasible tool to assess coronary flow velocity (CFV) in left anterior descending coronary artery (LAD) during stress echocardiography (SE).

Aim

To assess CFV response during coronary vasoconstrictor and vasodilator stimuli in INOCA patients.

Methods

In a prospective single center study, we enrolled 16 INOCA patients (age 60±12 years, 15 females) with previously normal angiograms. All underwent SE testing with hyperventilation (HYP, respiratory rate of 30 per min for 5') followed by supine bicycle exercise (HYP+EXE); and adenosine CFV evaluation (ADO, 0.84 mg/kg in 1 min) on the other day. The ratio of peak/rest changes of CFV during HYP in LAD was taken as an index of vasoconstriction, and CFV reserve was evaluated after EXE. An abnormal response to HYP was a CFV ratio <1.0 (vasoconstrictor response). An abnormal response to ADO was a CFV reserve <2.0 (blunted vasodilatory response). CFVR at peak HYP+ EXE was an indicator of endothelial dependent vasodilatation.

Results

The double product increased during HYP, in comparison to rest (13 337 vs 9858, p<0.001), and further increase with EXE (21 118 vs HYP, p<0.001). Chest pain or dyspnea were present in 2/16 pts during HYP, and in 5/16 patients during HYP+EXE (12.5% vs 31.25%, p=0.083). ST segment depression (≥1mm) was present in 1/16 patients during HYP, and 3/16 during HYP+EXE. Two patients showed regional wall motion abnormalities with HYP+EXE. CFVR response was blunted in 9/16 patients during HYP+EXE, and abnormal for vasoconstriction during HYP in 6. Vasodilation during ADO was preserved in all patients. There was significant difference between CFVR response during HYP+EXE and ADO (1.9±0.5 vs 2.4±0.4 respectively, p=0.039), and between CFVR HYP and ADO (1.2±0.3 vs 2.4±0.4, p<0.001).

Conclusion

In INOCA patients, HYP+EXE is a more powerful ischemic stress than HYP alone and unmasks abnormalities in regional wall motion and/or CFV response in over one- half of patients, likely unmasking the underlying abnormal coronary vasomotor response of large epicardial and/ or small coronary vessels. INOCA patients show profound heterogeneity of coronary vasomotor responses which can be detected with a combined vasodilator - vasoconstrictor SE approach with CFV assessment. The clarification of underlying coronary microcirculatory heterogeneity is the prerequisite for a personalized treatment, and can be easily extracted from CFV-SE. Normal INOCA hearts are all alike, every abnormal heart is abnormal in its own way.

Funding Acknowledgement

Type of funding source: None

The prognostic value of coronary flow reserve of left anterior descending artery in non-diagnostic or inconclusive stress echocardiography tests

Background

Relevant number of all stress echocardiography results are non-diagnostic or inconclusive. Such importance cannot be ignored as previous studies have shown that these patients have higher risk for adverse events. Non-invasive transthoracic Doppler derived coronary flow reserve (CFR) of left anterior descending (LAD) artery, as additional test, is an effective tool to predict adverse cardiac events in various clinical settings.

Purpose

The aim of this study was to investigate the value of CFR of LAD in predicting outcome.

Methods

122 patients, (35,8% with previous MI) with nondiagnostic stress echocardiography results (target heart rate not reached, chest pain without ECG and echo changes) and with inconclusive stress echocardiography results (target heart rate reached, chest pain with ECG changes and without echo changes) were referred for transthoracic

Doppler echocardiographic CFR assessment of LAD. CFR was calculated as the ratio between maximal hyperemic and baseline coronary flow velocity. CFR ≤2 was considered abnormal. All patients were followed for major adverse cardiac events (MACE): nonfatal myocardial infarction, hospitalization, revascularization (CABG or PCI) and death.

Results

Measured values of CFR LAD were in the range 1,52- 4,00 (mean: 2,4±0.44). CFR LAD was abnormal in 22 (18%), and preserved in 100 patients (82%). During median follow-up of 23 months (interquartile range 9–35), 14 patients underwent revascularization (2 had CABG, 12 had PCI). There were no myocardial infarctions, hospitalizations or cardiovascular deaths in the follow-up period. Patients with lower CFR values (CFR≤2) had a higher event rate and shorter event free survival time compared to those with CFR>2, event rate (9/22, 40,9% vs 5/98 5,1%; p<0.0001) and event free time (22±3 vs 33±1 months; p<0.0001) by Kaplan Maier analyses, (Log Rank 24.42; p<0.001).

Conclusions

Preserved CFR of LAD (>2.0) predicts excellent survival in patients with non-diagnostic and inconclusive stress echocardiography.

Funding Acknowledgement

Type of funding source: None

P328 Relation between CHA2DS2-VASc and impaired heart rate recovery in patients without inducible myocardial ischemia

Background

Heart rate recovery (HRR) has been shown to predict cardiovascular and all-cause morbidity and mortality in different populations. Recent studies have indicated the CHA2DS2-VASc score can be used as predictor of mortality in patients with coronary artery disease, without atrial fibrillation. However, the relation between these two parameters has not yet been documented.

The Aim: The aim of this study was to determine the relation between CHA2DS2-VASc score and impaired heart rate recovery in patients without inducible myocardial ischemia.

Methods

Our study comprised of 2699 consecutive patients (1319 male, 42.8%, average age 60 ± 11 years) who underwent treadmill exercise testing (stress echocardiography or stress echocardiography) according to Bruce protocol for the assessment of myocardial ischemia. We excluded patients with the systolic heart failure (left ventricle ejection fraction <45%) and those with inducible ischemia. CHA2DS2-VASc score was calculated according to the guidelines. Duke treadmill score, functional capacity (Metabolic Equivalents - METs), chronotropic competence (CC), body mass index (BMI) were calculated in all patients. HRR was calculated as the difference between heart rate at the peak stress and heart rate in the first minute of rest. Slow HRR was defined as ≤18 beats/min.

Results

Out of 2699 patients, 378 (12.3%) had a positive test and they were excluded from further analysis. Of the remaining 2321 patients, 251 (10.8%) had an impaired HRR, whereas 2070 (89.2%) had normal HRR. Previously known coronary artery disease (previous myocardial infarction, percutaneous coronary intervention or coronary artery bypass graft surgery) had 78 (3.4%) patients. Patients with impaired HRR had significantly higher CHA2DS2-VASc score (3.1 ± 1.3 vs 2.3 ± 1.2, p < 0.001), higher resting heart rate (76.9 ± 16.1 vs 73.3 ± 12.3bpm, p < 0.001), higher systolic blood pressure at rest (122.1 ± 13.9 vs 117.2 ± 13.4mmHg, p < 0.001), higher diastolic blood pressure at rest (73.7 ± 7.5 vs 72.3 ± 7.2mmHg, p < 0.001), higher rate of hyperlipproteinemia (176/251, 70.1% vs 1294/2070, 62.5%, p < 0.001), higher BMI (27.3 ± 3.6 vs 26.4± 3.6kg/m2, p < 0.001), shorter duration of the test (5.2 ± 1.8 vs 6.4 ± 1.9 minutes, p < 0.001). lower Duke score (4.6 ± 2.4 vs 6.1 ± 2.4 minutes, p < 0.001). lower MET (6.3 ± 1.8 vs 7.5 ± 1.9, p < 0.001) and higher rate of chronotropic incompetence (173/251, 68.9% vs 1036/2070, 50%, p < 0.001) compares to the patients with normal HRR. Multivariate predictors of impaired HRR were higher CHA2DS2-VASc score (p < 0.001), not achieved THR (p < 0.001), higher heart rate at rest (p = 0.001), higher systolic blood pressure at rest (p = 0.001) and shorter duration of test (p = 0.046).

Conclusion

CHA2DS2-VASc score is an independent predictor of impaired HRR in patients without inducible ischemia.

P1508The Coronary Arteriogenesis with combined Heparin and Exercise therapy in chronic refractory Angina (CARHEXA) trial: a double-blind randomized placebo-controlled stress echocardiographic study

Background

Coronary collateral circulation exerts protective effects on myocardial ischemia due to coronary artery disease (CAD) and can be promoted by exercise (E) with heparin (H) co-administration. Whether this arteriogenetic effects is accompanied by functional improvement of left ventricle (LV) during stress remains unknown.

Purpose

To establish the stress-induced functional effects on LV regional and global function of 2-week cycle of H+E in patients with “no-option” CAD.

Methods

In a prospective, single-center, double-blind, randomized, parallel-group study we recruited 32 “no-option” patients (27 males; mean age of 61±8 years), with stable angina and CTO, refractory to OMT, not suitable for revascularization and with E-induced ischemia. All underwent 2-week cycle of E (2 E test per day, 5 days a week) and were pre-treated with i.v. 0.9% saline or unfractionated H (100 IU/kg up to maximum of 5.000IU, 10 min prior to E). Canadian Class Score (CCS) and 12-lead E-ECG for time-to-1 mm ST-segment depression were assessed at entry and after treatment. LV function was evaluated during treadmill exercise with conventional and advanced imaging indices: Wall Motion Score Index (WMSI); Ejection Fraction (EF); Force (systolic blood pressure/end-systolic volume); Global Longitudinal Strain (GLS).

Results

Post-treatment exercise-time and CCS improved in both groups. In H+E patients exercise-time improved from 369.8±107.8 sec to 475.3±114.6 sec (p=0.001) while in E patients improved from 384±152.7 sec to 464.8±134.1 sec (p=0.019). CCS score changed in H+E from 2.6±0.7 to 1.9±0.7 (p=0.000), and in E group from 2.4±0.7 to 2.1±0.9 (p=0.046). At peak exercise, H+E was different from E group for EF and GLS (see Table).

Effects of H+E on SE parameters H+E p P+E p *H+E vs P+E STRESS Time 0 vs Time 1 Time 0 vs Time 1 Time 0 Time 1 WMSI 1.377 vs 1.279 0.005 1.404 vs 1.376 0.290 0.626 0.255 EF (%) 60.9 vs 64.8 0.016 61.2 vs 57.8 0.284 0.943 0.016 Force (mmHg/mL) 6.36 vs 6.5 0.158 5.82 vs 4.68 0.209 0.760 0.098 GLS (%) −16.96 vs −18.50 0.001 −15.79 vs −15.60 0.380 0.325 0.027 SE = stress echocardiography; H+E = heparin+exercise; P+E = placebo+exercise; Time 0 = before randomization; Time 1 = after 2-week therapy cycle. *p values.

Conclusion

A 2-week, H+E cycle is associated with improvement in regional and global LV function during exercise, concordantly shown by conventional (WMSI, EF) and advanced (GLS) echocardiographic indices of LV function. This integrates and supplements the classical objective index based on ST-segment depression, unable to localize and quantify the functional consequences of therapy on myocardial ischemia.

P2710Anti-ischemic effect of 2-week cycle of heparin plus exercise-to-ischemia twice daily in patients with “no-option” angina: the CARHEXA trial

Background

Coronary collateral circulation (CCC) exerts protective effects on myocardial ischemia due to coronary artery disease (CAD), but the anti-ischemic, pro-CCC effects of exercise (E) with or without heparin (H) co-administration remain unclear.

Purpose

To establish the anti-ischemic functional efficacy of 2-week cycle of E-to-ischemia twice daily, with or without unfractionated i.v. H immediately before E, in patients with “no-option” CAD

Methods

In a prospective, single-center, parallel group study design we recruited 32 “no-option” patients (27 males; mean age of 61±8 years) with at least one chronically occluded coronary artery and stable angina, refractory to optimal medical management, not suitable for revascularization therapy and with E-induced ischemia. All underwent a 2-week cycle of E (2 E test per day, 5 days a week, for 2 weeks) and were randomized, with a double-blind design, to i.v. placebo (0.9% saline) versus unfractionated H (100 IU/kg up to a maximum of 5.000 IU iv, 10 min prior to E). Seattle stable angina questionnaire (SAQ), 12-lead E-ECG for time-to-ischemia (treadmill exercise testing), and MDCT angiography for CCC imaging (Rentrop score, from 0= absent to 3= full opacification of occluded vessel) were assessed at entry and re-assessed after treatment for symptomatic, ECG, and anatomic end-points respectively.

Results

In H+E group (n=16), time to 1 mm ST segment depression (ST-D) increased, and CCC improved, p<0.05. On the contrary, no difference was observed in E group (n=16) in the pre-specified end-points (p>0.05) (see table). Clinically important change of more 10 points in SAQ was observed regarding physical limitation, angina stability and disease perception in H+E patients, and in only angina frequency in E group.

The ECG and angiographic results Heparin + Exercise Placebo + Exercise Rentrop baseline 0.73±0.88 1.06±1.06 Rentrop 2-week 1.6±0.99* 1.19±1.05 Time to ST-D base (s) 269±64 273±176 Time to ST-D 2-week (s) 328±65* 306±151 *p<0.05.

Conclusion

A 2-week, 10 E test cycles are well tolerated and effective particularly with H in ameliorating symptoms, E-induced ischemia and CCC in “no-option” CAD patients with refractory angina.

P1511Promising prognostic value of negative stress echocardiography in patients with incomplete revascularization after successful primary PCI

Background

The specific role of non-invasive functional testing in a risk stratification of patients with incomplete revascularization after primary percutaneous coronary intervention (pPCI) still needs to be evaluated. The aim of our study was to assess negative prognostic value of stress echocardiography (SECHO) after successful pPCI and incomplete revascularization of non-culprit lesions.

Methods

Our study consisted of 202 patients (mean age 59±10 years, male 142) successfully treated with pPCI, who performed SECHO according to Bruce protocol in order to assess residual ischemia in coronary artery with non-culprit lesion. Duke treadmill score, functional capacity (Metabolic Equivalents - METs), achieved target heart rate (THR), heart rate recovery (HRR), wall motion score index (WMSI) and ejection fraction were interrogated in all patients. Slow HRR was defined as ≤18 beats/min. Median follow-up of the patients was 70 months (IQR 55–83 months) for the occurrence of cardiovascular death and non-fatal myocardial infarction. We also assessed the independent predictors for the occurrence of the adverse events.

Results

Out of 202 patients, 42 (20.8%) had positive SECHO test, 4 patients (1.98%) had died due to non-cardiac causes and 7 patients (3.5%) were lost to follow-up. From the remaining 149 patients with negative SECHO, 13 (8.7%) had an adverse event (7 cardiovascular deaths and 6 non-fatal MI). Negative predictive value of SECHO test was 91.3%. Univariate predictors of adverse events were slow HRR (HR 4.343 [95% CI 1.473–14.011], p=0.008), and not achieved THR (HR 0.322 [95% CI 0.105–0.985], p=0.047). By multivariate analysis, only slow HRR remained independent predictor of adverse events (HR 3.324 [95% CI 1.013–10.906], p=0.048).

Conclusion

SECHO test has excellent negative prognostic value in patients with incomplete revascularization of non-culprit lesions after successful pPCI. Still, particular care should be taken to the patients with slow HRR and negative SECHO due to increased risk for the occurrence of adverse events.

Acknowledgement/Funding

Ministry of Education and Science of the Republic of Serbia (Grant No III41022)