Asymptomatic Aortic Stenosis: From Risk Stratification to Treatment

Our understanding of the natural history of aortic stenosis has significantly increased over the last decade. There have been considerable advances in the diagnosis and risk stratification of patients with aortic stenosis and in surgical and anesthetic techniques. In addition, transcatheter aortic valve replacement has established itself as a viable alternative to surgical management. Inevitably, these developments have raised questions regarding the merits of waiting for symptom onset in asymptomatic patients with severe aortic stenosis before offering treatment. Recent observational and randomized trial data suggest that early intervention in asymptomatic patients with severe aortic stenosis and normal left ventricular function may confer a prognostic advantage to a watchful waiting strategy. In this review, we highlight advances in the management and risk stratification of patients with asymptomatic severe aortic stenosis with particular consideration of recent findings supporting early valvular intervention.

Acute Coronary Syndrome Following Transcatheter Aortic Valve Replacement

Extending the indication of transcatheter aortic valve replacement (TAVR) to younger and lower-risk patients naturally results in longer life expectancy and survival rates after the intervention. The longer life expectancy of these patients leads to an increased possibility of future acute coronary events, necessitating the development of effective and appropriate treatment strategies. Acute coronary syndromes (ACS) in patients with previous TAVR procedures present with modified clinical characteristics when compared to the non-TAVR population. In populations with prior TAVR procedures, plaque rupture remains the main cause of ACS. However, unlike the non-TAVR population, there is an increased frequency of nonatherotrombotic mechanisms, like emboli and mechanical obstruction of coronary ostia by valve components. The main observation related to the treatment of ACS TAVR patients is the significantly lower percentage of patients undergoing invasive management. Furthermore, ACS in TAVR patients is associated with poor prognosis, higher long-term mortality rates, and higher incidence of MACE. It is surprising that considering this significant and increasingly recognized issue, there are only a few studies that have investigated ACS after TAVR. The scope of the present review is to address available data about ACS following TAVR, focusing on incidence, timing, mechanism, and causes. We also examined current knowledge regarding optimal invasive treatment and analyzed short and long-term clinical outcomes.

Asymptomatic Severe and Moderate Aortic Stenosis: Time for Appraisal of Treatment Indications

Over the last decades, we have witnessed considerable improvements in diagnostics and risk stratification of patients with significant aortic stenosis (AS), paralleled by advances in operative and anesthetic techniques. In addition, accumulating evidence points to the potential benefit of early valve replacement in such patients prior to the onset of symptoms. In parallel, interventional randomized trials have proven the benefit of transcatheter aortic valve replacement in comparison to a surgical approach to valve replacement over a broad risk spectrum in symptomatic patients with AS. This article reviews contemporary management approaches and scrutinizes open questions regarding timing and mode of intervention in asymptomatic patients with severe AS. We also discuss the challenges surrounding the management of symptomatic patients with moderate AS as well as emerging dilemmas related to the concept of a life-long treatment strategy for patients with AS.

Impact of diabetes on remodelling, microvascular function and exercise capacity in aortic stenosis

OBJECTIVE

To characterise cardiac remodelling, exercise capacity and fibroinflammatory biomarkers in patients with aortic stenosis (AS) with and without diabetes, and assess the impact of diabetes on outcomes.

METHODS

Patients with moderate or severe AS with and without diabetes underwent echocardiography, stress cardiovascular magnetic resonance (CMR), cardiopulmonary exercise testing and plasma biomarker analysis. Primary endpoint for survival analysis was a composite of cardiovascular mortality, myocardial infarction, hospitalisation with heart failure, syncope or arrhythmia. Secondary endpoint was all-cause death.

RESULTS

Diabetes (n=56) and non-diabetes groups (n=198) were well matched for age, sex, ethnicity, blood pressure and severity of AS. The diabetes group had higher body mass index, lower estimated glomerular filtration rate and higher rates of hypertension, hyperlipidaemia and symptoms of AS. Biventricular volumes and systolic function were similar, but the diabetes group had higher extracellular volume fraction (25.9%±3.1% vs 24.8%±2.4%, p=0.020), lower myocardial perfusion reserve (2.02±0.75 vs 2.34±0.68, p=0.046) and lower percentage predicted peak oxygen consumption (68%±21% vs 77%±17%, p=0.002) compared with the non-diabetes group. Higher levels of renin (log10renin: 3.27±0.59 vs 2.82±0.69 pg/mL, p<0.001) were found in diabetes. Multivariable Cox regression analysis showed diabetes was not associated with cardiovascular outcomes, but was independently associated with all-cause mortality (HR 2.04, 95% CI 1.05 to 4.00; p=0.037).

CONCLUSIONS

In patients with moderate-to-severe AS, diabetes is associated with reduced exercise capacity, increased diffuse myocardial fibrosis and microvascular dysfunction, but not cardiovascular events despite a small increase in mortality.

Contemporary Challenges of Regenerative Therapy in Patients with Ischemic and Non-Ischemic Heart Failure

It has now been almost 20 years since first clinical trials of stem cell therapy for heart repair were initiated. While initial preclinical data were promising and suggested that stem cells may be able to directly restore a diseased myocardium, this was never unequivocally confirmed in the clinical setting. Clinical trials of cell therapy did show the process to be feasible and safe. However, the clinical benefits of this treatment modality in patients with ischemic and non-ischemic heart failure have not been consistently confirmed. What is more, in the rapidly developing field of stem cell therapy in patients with heart failure, relevant questions regarding clinical trials' protocol streamlining, optimal patient selection, stem cell type and dose, and the mode of cell delivery remain largely unanswered. Recently, novel approaches to myocardial regeneration, including the use of pluripotent and allogeneic stem cells and cell-free therapeutic approaches, have been proposed. Thus, in this review, we aim to outline current knowledge and highlight contemporary challenges and dilemmas in clinical aspects of stem cell and regenerative therapy in patients with chronic ischemic and non-ischemic heart failure.

Do all patients with asymptomatic severe aortic stenosis need treatment?

INTRODUCTION

Although guidelines recommend a watchful waiting strategy for patients with asymptomatic severe aortic stenosis, there have been considerable advancements in surgical and anaesthetic techniques along with the success of transcatheter aortic valve replacement (AVR) as a viable alternative to surgical AVR. Inevitably, these developments have raised questions as to whether or not there is still merit in waiting for symptoms to ensue before treatment may offered to these patients.

AREA COVERED

The principal purpose of this paper is to review the data supporting earlier intervention in patients with asymptomatic severe aortic stenosis, and to project the implications these and other ongoing trials will have on indications for AVR in asymptomatic patients in the future.

EXPERT OPINION

The threshold for intervention in certain subgroups of asymptomatic patients with severe AS has already been lowered. The next frontier will inevitably be determining whether all patients with severe AS should undergo AVR irrespective of their symptomatic status.

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.

Early aortic valve replacement improves exercise capacity in truly asymptomatic patients with severe aortic stenosis

Background

Exercise capacity is a strong predictor of morbidity and mortality overall. In severe aortic stenosis (AS) ustained pressure overload during watchful waiting is associated with LV structural and functional deterioration and impaired clinical outcome both pre- and post aortic valve replacement (AVR). The effect of early surgical aortic valve replacement (SAVR) in asymptomatic patients with severe AS and normal left ventricular function on exercise capacity in unknown.

Aim

We investigated whether the early surgical AVR in truly asymptomatic patients with severe aortic stenosis and normal LVEF improves the exercise capacity.

Methods

This is a sub-analysis or the AVATAR trial (NCT02436655), which is international prospective randomized controlled trial that evaluated the safety and efficacy of early SAVR in the treatment of asymptomatic patients with severe AS, according to common criteria (valve area ≤1 cm2 with aortic jet velocity &gt;4 m/s or a mean transaortic gradient ≥40 mm Hg), and with normal left ventricular function. Patients underwent cardiopulmonary exercise testing (supine bicycle, ramp protocol, 15 W/min) at the baseline and 12 months following the randomization. Patients who had positive exercise testing at baseline visit were excluded. We compared the value of workload (in WATs), VO2 max, VO2 AT, VE/VCO2 and PETCO2 slope at the inclusion and at 12 months.

Results

Total of 157 patients (mean age, 67 years; 57% men) were randomly allocated to early surgery (n=78) or conservative treatment (n=79). Mean LVEF and Vmax in early surgery and conservative treatment group were 70% and 4.5m/s and 69% and 4.5m/s, respectively. After 12 months in patients with conservative treatment there was a slight decrease in the values of workload, VO2 max, VO2 AT, VE/VCO2 and PETCO2 slope, but without statistical significance. However operated patients showed a significant increase in workload (115.4±38.4 watts at 12 months vs 104.8±42.2 at inclusion, p=0.038) and VO2 max (19.7±6.8 at 12 months vs 16.2±5.4 at the inclusion, p=0.048), while there was slight increase in the values of VO2 AT, VEVCO2 and PETCO2 but without statistical significance.

Conclusion

Early SAVR improve the functional capacity in asymptomatic patients with severe aortic stenosis and normal left ventricular ejection fraction

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 &lt;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&lt;0.001) and 88% (kappa=0.731, p&lt;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.

Challenges in Diagnosis and Functional Assessment of Coronary Artery Disease in Patients With Severe Aortic Stenosis

More than half of patients with severe aortic stenosis (AS) over 70 years old have coronary artery disease (CAD). Exertional angina is often present in AS-patients, even in the absence of significant CAD, as a result of oxygen supply/demand mismatch and exercise-induced myocardial ischemia. Moreover, persistent myocardial ischemia leads to extensive myocardial fibrosis and subsequent coronary microvascular dysfunction (CMD) which is defined as reduced coronary vasodilatory capacity below ischemic threshold. Therefore, angina, as well as noninvasive stress tests, have a low specificity and positive predictive value (PPV) for the assessment of epicardial coronary stenosis severity in AS-patients. Moreover, in symptomatic patients with severe AS exercise testing is even contraindicated. Given the limitations of noninvasive stress tests, coronary angiography remains the standard examination for determining the presence and severity of CAD in AS-patients, although angiography alone has poor accuracy in the evaluation of its functional severity. To overcome this limitation, the well-established invasive indices for the assessment of coronary stenosis severity, such as fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR), are now in focus, especially in the contemporary era with the rapid increment of transcatheter aortic valve replacement (TAVR) for the treatment of AS-patients. TAVR induces an immediate decrease in hyperemic microcirculatory resistance and a concomitant increase in hyperemic flow velocity, whereas resting coronary hemodynamics remain unaltered. These findings suggest that FFR may underestimate coronary stenosis severity in AS-patients, whereas iFR as the non-hyperemic index is independent of the AS severity. However, because resting coronary hemodynamics do not improve immediately after TAVR, the coronary vasodilatory capacity in AS-patients treated by TAVR remain impaired, and thus the iFR may overestimate coronary stenosis severity in these patients. The optimal method for evaluating myocardial ischemia in patients with AS and co-existing CAD has not yet been fully established, and this important issue is under further investigation. This review is focused on challenges, limitations, and future perspectives in the functional assessment of coronary stenosis severity in these patients, bearing in mind the complexity of coronary physiology in the presence of this valvular heart disease.

Aortic Valve Replacement Versus Conservative Treatment in Asymptomatic Severe Aortic Stenosis: The AVATAR Trial

BACKGROUND

Surgical aortic valve replacement (SAVR) represents a class I indication in symptomatic patients with severe aortic stenosis (AS). However, indications for early SAVR in asymptomatic patients with severe AS and normal left ventricular function remain debated.

METHODS

The AVATAR trial (Aortic Valve Replacement Versus Conservative Treatment in Asymptomatic Severe Aortic Stenosis) is an investigator-initiated international prospective randomized controlled trial that evaluated the safety and efficacy of early SAVR in the treatment of asymptomatic patients with severe AS, according to common criteria (valve area ≤1 cm² with aortic jet velocity >4 m/s or a mean transaortic gradient ≥40 mm Hg), and with normal left ventricular function. Negative exercise testing was mandatory for inclusion. The primary hypothesis was that early SAVR would reduce the primary composite end point of all-cause death, acute myocardial infarction, stroke, or unplanned hospitalization for heart failure compared with a conservative strategy according to guidelines. The trial was designed as event-driven to reach a minimum of 35 prespecified events. The study was performed in 9 centers in 7 European countries.

RESULTS

Between June 2015 and September 2020, 157 patients (mean age, 67 years; 57% men) were randomly allocated to early surgery (n=78) or conservative treatment (n=79). Follow-up was completed in May 2021. Overall median follow-up was 32 months: 28 months in the early surgery group and 35 months in the conservative treatment group. There was a total of 39 events, 13 in early surgery and 26 in the conservative treatment group. In the early surgery group, 72 patients (92.3%) underwent SAVR with operative mortality of 1.4%. In an intention-to-treat analysis, patients randomized to early surgery had a significantly lower incidence of primary composite end point than those in the conservative arm (hazard ratio, 0.46 [95% CI, 0.23-0.90]; P=0.02). There was no statistical difference in secondary end points, including all-cause mortality, first heart failure hospitalizations, major bleeding, or thromboembolic complications, but trends were consistent with the primary outcome.

CONCLUSIONS

In asymptomatic patients with severe AS, early surgery reduced a primary composite of all-cause death, acute myocardial infarction, stroke, or unplanned hospitalization for heart failure compared with conservative treatment. This randomized trial provides preliminary support for early SAVR once AS becomes severe, regardless of symptoms. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02436655.

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&lt;0.001). ROC analysis identifies the optimal CFVR during peak DOB cut-off value &lt;2.1 (AUC 0.985, 95% CI: 0.965–1.000, p&lt;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&lt;0.001). Multivariate logistic regression analysis showed that percent DS at end-diastole was the only independent predictor of ischemic CFVR value &lt;2.1 (OR: 1.136, 95% CI: 1.045–1.235, p=0.003).

Conclusion

A cut-off value &lt;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.

Five-Year Outcomes in Bariatric Surgery Patients

Background and objectives: Obesity presents as a multifactorial, pandemic disease that arises as a consequence of unequal energy intake and energy consumption. Obesity adversely affects the quality of life, leading not only to disability, but also to various other disorders. Bariatric surgery is the most effective method for achieving significant and sustained weight loss in individuals with extreme obesity. The aim of this study was to examine how well surgically induced weight loss is maintained after five years of follow-up and its effects on cardiovascular risk factors and outcome. Materials and Methods: This is a retrospective cross-sectional study of 66 patients with morbid obesity, with body mass index (BMI) ≥ 40 kg/m² or BMI ≥ 35 kg/m² and obesity-related health conditions, aged 20 to 61 years, mostly women (77.3%) who underwent laparoscopic Roux-en-Y gastric bypass surgery. Results: Average follow-up was 6.42 years (95% CI 6.30–6.54 years) after surgery, with survival rate of 97% in operated individuals. There was a statistically significant reduction of weight and body mass index 6 months and 5 years after surgery in comparison to the initial values (p < 0.001). Of 62 patients who presented weight loss at the end of the follow-up period, 38 were able to maintain the amount of weight loss that was attained 6 months after surgery, while 24 patients regained weight compared to their postoperative weight at 6 months. Two patients reported no weight loss after treatment. Significant weight reduction was associated with better control of diabetes and increased self-reported physical activity at 6 months and 5 years after surgery, as well as with a reduction of the use of anti-diabetic and anti-hypertensive medications. Conclusions: Our research demonstrates a positive long-term impact of bariatric surgery on patients’ health conditions, significant and sustained weight loss, and decrease in BMI, which were associated with a reduction of co-morbidities and risk factors for cardiovascular diseases.

Gender specific differences in functional capacity in asymptomatic patients with isolated severe aortic stenosis

 

Risk stratification as well as treatment decision in asymptomatic patients with isolated severe aortic stenosis (AS) is matter of ongoing debate. It has been known that gender-specific difference in left ventricular reaction to AS exists. Female gender has also been linked to increased risk of adverse events after surgical AVR but with better outcome after TAVI. We investigated whether there is a gender difference in functional capacity in asymptomatic patients with isolated severe AS.

Asymptomatic patients with severe AS were prospectively enrolled and underwent cardiopulmonary stress-echocardiography exercise testing (ESE-CPET) on supine ergobicycle, ramp protocol, 15 W/min. Patients with ischemia positive test were excluded (ECG and/or echo)

There were 139 patients, 61 women. There were no gender differences in age (66.36 vs 67.37, p=ns), echo parameters (Vmax 4.54 vs 4.48m/s, AVA 0.62 vs 0.68cm2, and Pmean 52.6 vs 53.8mmHg, all p=ns), LVEF (68.56 vs 70.90%, p=ns), e/E' (12.74 vs 14.45, p=ns), BNP (112.51 vs 110.55 pg/ml, p=ns) and valvulo-arterial impedance (4.65 vs 5.14mm Hg·ml–1·m2, p=0.07). Women had higher body mass index (29.05 vs 26.95, p=0.022), lower VO2max (12.96 vs 17.93 ml/kg/m2, p=0.001) and higher VE/VCO2 slope (33.69 vs 29.01, p=0.003). Univariable and multivariable linear regression analysis were used to test the relation between various clinical and echocardiographic parameters and VO2max. The variables independently associated with the VO2max are shown in table 1, with female gender being the strongest independent predictor of VO2max

Conclusion

Female gender is independent predictor of decreased functional capacity, even when adjusting for other variables, including BMI and echo markers of AS severity. Further studies are needed to determine whether this finding affects the course and outcome of the disease

Funding Acknowledgement

Type of funding source: None

P1866Catheter-ablation of paroxysmal atrial fibrillation is associated with improvement of maximal cardiopulmonary exercise capacity

Background and purpose

Catheter-ablation (CA) of paroxysmal atrial fibrillation (AF) is associated with improvement in symptoms and quality of life (QoL), whilst the effects on functional capacity are underreported. We studied the change in cardiopulmonary exercise testing (CPET) indices of functional capacity from baseline to follow-up in patients undergoing their first CA for paroxysmal AF.

Methods

Consecutive patients who underwent their first CA for paroxysmal AF in our center during 2015, with a >12-month post-procedural follow-up were included. All patients completed the CPET and SF-36 (Short Form Health Survey) questionnaire to evaluate maximal functional capacity and QoL, respectively, at baseline (prior to CA) and 1 year post-CA. The follow-up 24h-Holter-monitoring was performed at 1, 3, 6 and 12 months after CA; finding of any atrial tachyarrhythmia lasting >30 sec was considered the arrhythmia recurrence.

Results

Study group consisted of 50 patients (the mean age 57±12 years, males 76%). The mean left ventricular ejection fraction and left atrial diameter were 61±8% and 41±6 mm, respectively. All patients were free of heart failure; the commonest comorbidities were hypertension (65%) and diabetes mellitus (21%). The follow-up CPET 1 year post CA demonstrated an improvement in maximal functional capacity compared to baseline values, with significant increase in maximal load (123±38 vs. 134±33 W, p=0.012), peak oxygen consumption (VO2max, 18±5 vs. 20±4 mL kg–1 min–1, p=0.001) and peak breathing equivalent (EQ-O2, 28±4 vs. 29±4, p=0.020). The AF-free patients (n=40) had a greater 1-year improvement in work time (22±129 vs. −71±123 sec, p=0.008) and maximal load (15±24 vs. −6±26 W, p=0.005) compared with those expiriencing AF recurrence post-CA (n=10). There was a significant correlation between the 1-year change in SF-36 score and the increase in maximal load (ρ=0.26, p=0.018) and between the 1-year change in SF-36 score and the prolongation of work time (ρ=0.27, p=0.017).

Conclusion

Our study suggests that CA of paroxysmal AF favourably affects the maximal functional capacity, especially in patients with stable sinus rhythm following the procedure. The increase in functional capacity is followed by QoL improvement. This should be considered in treatment decision-making.

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)

Aortic stenosis and diabetes mellitus: An ominous combination

Aortic stenosis and diabetes mellitus are both progressive diseases which, if left untreated, result in significant morbidity and mortality. There is evidence that the prevalence of diabetes is substantially increased in patients with aortic stenosis and those with diabetes have increased rates of progression from mild to severe aortic stenosis. There are good data supporting the hypothesis that aortic stenosis and diabetes mellitus are associated with diabetes mellitus being detrimental towards the quality of life and survival of patients. Thus, a thorough understanding of the pathogenesis of both of these disease processes and the relationship between them aids in designing appropriate preventive and therapeutic approaches. This review aims to give a comprehensive and up-to-date insight into the influence of diabetes mellitus on patients with degenerative aortic stenosis, as well as the prognosis and therapeutic approach to these patients.

The Amount of Weight Loss Six Months after Bariatric Surgery: It Makes a Difference

BACKGROUND

Bariatric surgery, especially Roux-en-Y gastric bypass (RYGB), has become the most frequently used therapy for morbid obesity.

OBJECTIVES

The aim of this study was to examine the effects of surgically induced weight loss on cardiopulmonary function 6 months after the procedure, as well as the effect of such an intervention on well-known risk factors for cardiovascular diseases.

METHODS

This is a cross-sectional study on 66 morbidly obese patients (BMI ≥40 or ≥35 kg/m2 with present comorbidities), comparing their cardiopulmonary function prior to and 6 months after RYGB surgery.

RESULTS

The substantial amount of weight loss (29.80 ± 13.27 kg) after RYGB surgery was associated with significant reduction of comorbidities, especially diabetes and sedentary lifestyle (p = 0.005 and p = 0.002, respectively). Regarding functional capacity, there was significant increase in peak oxygen uptake (VO2 peak, p = 0.003), duration of exercise testing, metabolic equivalents (exercise time and METs, p < 0.001), and in peak O2 pulse. These findings were particularly pronounced in a group of patients who had lost more than 18% of initial weight.

CONCLUSIONS

Reduction of body weight after RYGB surgery is associated with significantly improved cardiorespiratory function 6 months after surgery, especially in patients who lost more than 18% of their initial body weight. In addition, substantial decreases in body weight were also associated with a reduction of cardiovascular risk factors such as diabetes, smoking, hypertriglyceridemia, and sedentary lifestyle.

Degenerative Mitral Stenosis: From Pathophysiology to Challenging Interventional Treatment

Mitral stenosis (MS) is characterized by obstruction of left ventricular inflow as a result of narrowing of the mitral valve orifice. Although its prevalence has declined over the last decade, especially in developed countries, it remains an important cause of morbidity and mortality.  The most often cause of MS worldwide is still postrheumatic mitral valve disease. However, in developed countries, degenerative or calcific changes cause MS in a siginificant proportion of patients. Although the range of treatment for mitral valve disease has grown over the years in parallel with transcatheter therapies for aortic valve disease, these improvements in mitral valve disease therapy have experienced slower development. This is mainly due to the more complex anatomy of the mitral valve and entire mitral apparatus, and the interplay of the mitral valve with the left ventricle which hinders the development of effective implantable mitral valve devices. This is especially the case with degenerative MS where percutaneous or surgical comissurotomy is rarely employed due to the presence of extensive annular calcification and at the base of leaflets, without associated commissural fusion. However, the last few years have witnessed innovations in transcatheter interventional procedures for degenerative MS which consequently hinted that in the future, transcatheter mitral valve replacement could be the treatment of choice for these patients.

Stress hormones at rest and following exercise testing predict coronary artery disease severity and outcome

OBJECTIVES

Despite considerable knowledge regarding the importance of stress in coronary artery disease (CAD) pathogenesis, its underestimation persists in routine clinical practice, in part attributable to lack of a standardized, objective assessment. The current study examined the ability of stress hormones to predict CAD severity and prognosis at basal conditions as well as during and following an exertional stimulus.

MATERIALS AND METHODS

Forty Caucasian subjects with significant coronary artery lesions (≥50%) were included. Within 2 months of coronary angiography, cardiopulmonary exercise testing (CPET) on a recumbent ergometer was performed in conjunction with stress echocardiography (SE). At rest, peak and after 3 min of recovery following CPET, plasma levels of cortisol, adrenocorticotropic hormone (ACTH) and NT-pro-brain natriuretic peptide (NT-pro-BNP) were measured by immunoassay sandwich technique, radioimmunoassay, and radioimmunometric technique, respectively. Subjects were subsequently followed a mean of 32 ± 10 months.

RESULTS AND DISCUSSION

Mean ejection fraction was 56.7 ± 9.6%. Subjects with 1-2 stenotic coronary arteries (SCA) demonstrated a significantly lower plasma cortisol levels during CPET compared to those with 3-SCA (p < .05), whereas ACTH and NT-pro-BNP were not significantly different (p > .05). Among CPET, SE, and hormonal parameters, cortisol at rest and during CPET recovery demonstrated the best predictive value in distinguishing between 1-, 2-, and 3-SCA [area under ROC curve 0.75 and 0.77 (SE = 0.11, 0.10; p = .043, .04) for rest and recovery, respectively]. ΔCortisol peak/rest predicted cumulative cardiac events (area under ROC curve 0.75, SE = 0.10, p = .049).

CONCLUSIONS

Cortisol at rest and following an exercise test holds predictive value for CAD severity and prognosis, further demonstrating a link between stress and unwanted cardiac events.

Exercise capacity is not impaired after acute alcohol ingestion: a pilot study

The usage of alcohol is widespread, but the effects of acute alcohol ingestion on exercise performance and the stress hormone axis are not fully elucidated.We studied 10 healthy white men, nonhabitual drinkers, by Doppler echocardiography at rest, spirometry, and maximal cardiopulmonary exercise test (CPET) in two visits (2-4 days in between), one after administration of 1.5 g/kg ethanol (whisky) diluted at 15% in water, and the other after administration of an equivalent volume of water. Plasma levels of NT-pro-BNP, cortisol, and adrenocorticotropic hormone (ACTH) were also measured 10 min before the test, at maximal effort and at the third minute of recovery. Ethanol concentration was measured from resting blood samples by gas chromatography and it increased from 0.00 ± 0.00 to 1.25 ± 0.54‰ (P < 0.001). Basal echocardiographic and spirometric parameters were normal and remained so after acute alcohol intake, whereas ACTH, cortisol, and NT-pro-BNP nonsignificantly increased in all phases of the test. CPET data suggested a trend toward a slight reduction of exercise performance (peak VO2 = 3008 ± 638 vs. 2900 ± 543 ml/min, ns; peak workload = 269 ± 53 vs. 249 ± 40 W, ns; test duration 13.7 ± 2.2 vs. 13.3 ± 1.7 min, ns; VE/VCO2 22.1 ± 1.4 vs. 23.3 ± 2.9, ns). Ventilatory equivalent for carbon dioxide at rest was higher after alcohol intake (28 ± 2.5 vs. 30.4 ± 3.2, P = 0.039) and maximal respiratory exchange ratio was lower after alcohol intake (1.17 ± 0.02 vs. 1.14 ± 0.04, P = 0.04). In conclusion, we showed that acute alcohol intake in healthy white men is associated with a nonsignificant exercise performance reduction and stress hormone stimulation, with an unchanged exercise metabolism.

Gauging the response to cardiac resynchronization therapy: The important interplay between predictor variables and definition of a favorable outcome

AIMS

Selection of patients who are viable candidates for cardiac resynchronization therapy (CRT), prediction of the response to CRT as well as an optimal definition of a favorable response, all require further exploration. The purpose of this study was to evaluate the interplay between the prediction of the response to CRT and the definition of a favorable outcome.

METHODS

Seventy patients who received CRT were included. All patients met current guideline criteria for CRT. Forty-three echocardiographic parameters were evaluated before CRT and at 1, 3, 6, and 12 months. M-mode, 2D echocardiography, and Doppler imaging were used to quantify left ventricular (LV) systolic and diastolic function, mitral regurgitation, right ventricular systolic function, pulmonary artery pressure, and myocardial mechanical dyssynchrony. The following definitions of a favorable CRT response were used: left ventricular ejection fraction (LVEF) improvement more >5% acutely following CRT, LVEF improvement >20% at 12-month follow-up, and a LV end-systolic volume (LVESV) decrease >15% at 12-month follow-up.

RESULTS

For the LVEF improvement >5%, the best predictor was isovolumetric relaxation time (IVRT; P=.035). For improvement of LVEF >20%, the best predictors were left ventricular stroke index (LVSI; P=.044) and left ventricular fractional shortening (LVFS; P=.031). For the drop in left ventricular systolic volume (LVESV >15%), the best predictor was septal-to-lateral wall delay (ΔT) (P=.043, RR=1.023, 95% CI for RR=1.001-1.045).

CONCLUSION

The definition of a favorable CRT response influenced the optimal predictor variable(s). Standardization of defining a favorable response to CRT is needed to guide clinical decision making processes.

Pea seed-borne mosaic virus in Field Pea: Widespread Infection, Genetic Diversity, and Resistance Gene Effectiveness

From 2013 to 2015, incidences of Pea seed-borne mosaic virus (PSbMV) infection were determined in semi-leafless field pea (Pisum sativum) crops and trial plots growing in the Mediterranean-type environment of southwest Australia. PSbMV was found at incidences of 2 to 51% in 9 of 13 crops, 1 to 100% in 20 of 24 cultivar plots, and 1 to 57% in 14 of 21 breeding line plots. Crops and plots of 'PBA Gunyah', 'Kaspa', and 'PBA Twilight' were frequently PSbMV infected but none of PSbMV resistance gene sbm1-carrying 'PBA Wharton' plants were infected. In 2015, 14 new PSbMV isolates obtained from these various sources were sequenced and their partial coat protein (CP) nucleotide sequences analyzed. Sequence identities and phylogenetic comparison with 39 other PSbMV partial CP nucleotide sequences from GenBank demonstrated that at least three PSbMV introductions have occurred to the region, one of which was previously unknown. When plants of 'Greenfeast' and PBA Gunyah pea (which both carry resistance gene sbm2) and PBA Wharton and 'Yarrum' (which carry sbm1) were inoculated with PSbMV pathotype P-2 isolate W1, resistance was overcome in a small proportion of plants of each cultivar, showing that resistance-breaking variants were likely to be present. An improved management effort by pea breeders, advisors, and growers is required to diminish infection of seed stocks, avoid sbm gene resistance being overcome in the field, and mitigate the impact of PSbMV on seed yield and quality. A similar management effort is likely to be needed in field pea production elsewhere in the world.

Noninvasive assessment of myocardial bridging by coronary flow velocity reserve with transthoracic Doppler echocardiography: vasodilator vs. inotropic stimulation

BACKGROUND

To consider hemodynamic assessment of myocardial bridging (MB) adequate, it is believed that inotropic stimulation with dobutamine should be estimated because its dynamic nature depends on the degree of extravascular coronary compression. This study evaluated comparative assessment of hemodynamic relevance of MB using coronary flow velocity reserve (CFVR) measurements by transthoracic Doppler echocardiography (TTDE) with vasodilatative and inotropic challenges.

METHODS

This prospective study included forty-four patients with angiographic evidence of isolated MB of the left anterior descending coronary artery (LAD) and systolic compression of ≥50% diameter stenosis. All patients were evaluated by exercise stress-echocardiography (ExSE) test for signs of myocardial ischemia, and CFVR of the distal segment of LAD during iv.infusion of adenosine (ADO:140μg/kg/min) and iv.infusion of dobutamine (DOB:10-40μg/kg/min), separately.

RESULTS

Exercise-SE was positive for myocardial ischemia in 8/44 (18%) of patients. CFVR during ADO was significantly higher than CFVR during peak DOB (2.85±0.68 vs. 2.44±0.48, p=0.002). CFVR during peak DOB was significantly lower in SE-positive group in comparison to SE-negative group (2.01±0.16 vs. 2.54±0.47, p<0.001), but not for ADO (2.47±0.51 vs. 2.89±0.70, p=0.168), respectively. Multivariable logistic analysis showed that CFVR peak DOB was the most significant predictor of functional significant MB (OR 0.011, 95%CI: 0.001-0.507, p=0.021). Receiver-operating characteristic curves have shown that TTDE-CFVR obtained by high-dose of dobutamine infusion is better than those by adenosine regarding to functional status of MB (AUC 0.861, p=0.004; AUC 0.674, p=0.179, respectively).

CONCLUSIONS

Non-invasive CFVR measurement by TTDE during inotropic stimulation, in comparison to vasodilation, provides more reliable functional evaluation of MB.

Diabetes mellitus and coronary microvascular function in asymptomatic patients with severe aortic stenosis and nonobstructed coronary arteries

BACKGROUND AND AIM

Coronary flow reserve is impaired in asymptomatic patients with aortic stenosis and has a prognostic value. We investigated whether the type II diabetes mellitus additionally impairs microvascular circulation assessed by coronary flow reserve in patients with asymptomatic severe aortic stenosis, normal left ventricular ejection fraction and nonobstructed coronary arteries.

METHODS

A total of 128 patients, mean age of 66.35 ± 10.51 (58.6% males), with severe aortic stenosis and normal left ventricular ejection fraction were enrolled in this study. Patients with diabetes mellitus, those who were treated for diabetes mellitus or had documentation confirming the diagnosis of diabetes mellitus, were considered. All patients underwent coronary angiography and had no obstructive coronary disease (defined as having no stenosis >50% in diameter), standard transthoracic Doppler-echocardiographic study and adenosine stress transthoracic echocardiography for coronary flow reserve measurement.

RESULTS

Diabetes mellitus was present in 26 patients (20.31%). There was no significant difference in aortic stenosis severity between diabetic and non-diabetic patients [aortic valve area (0.81 ± 0.18 vs 0.85 ± 0.15 cm(2)) and Vmax (4.20 ± 0.57 vs 4.21 ± 0.48 m/s)]. Mean coronary flow reserve in diabetic patients was 1.98 ± 0.48, while mean coronary flow reserve in non-diabetic patients was 2.64 ± 0.54 (p < 0.01). Diabetes mellitus was independent predictor of coronary flow reserve [B = -0.636, 95% confidence interval (-0.916 to -0.368), p < 0.001].

CONCLUSION

Diabetes mellitus additionally impairs coronary microvascular function in asymptomatic patients with severe aortic stenosis and nonobstructed coronary arteries.

Rationale and design of the Aortic Valve replAcemenT versus conservative treatment in Asymptomatic seveRe aortic stenosis (AVATAR trial): A randomized multicenter controlled event-driven trial

Aortic valve replacement (AVR) therapy is an obvious choice for symptomatic severe aortic stenosis (AS) patients as it improves symptoms, left ventricular function, and survival. The treatment decisions and indication for AVR in asymptomatic patients with severe AS and normal left ventricular ejection fraction are less well established and the subject of ongoing debate. Many efforts have been made to define the best treatment option in asymptomatic AS patients with normal left ventricular ejection fraction. Retrospective and observational data imply that elective AVR for asymptomatic severe AS may lead to improvement in outcomes in comparison to surgery performed after onset of symptoms. The AVATAR trial will aim to assess outcomes among asymptomatic AS patients randomized to either elective early AVR or medical management with vigilant follow-up. In the latter group, AVR would be delayed until either the onset of symptoms or changes in predefined echocardiographic parameters. To the best of the authors' knowledge, it will be the first large prospective, randomized, controlled, multicenter clinical trial that will evaluate the safety and efficacy of elective AVR in this specific group of patients.

The combined exercise stress echocardiography and cardiopulmonary exercise test for identification of masked heart failure with preserved ejection fraction in patients with hypertension

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is commonly associated with hypertension (HTN). However, resting echocardiography (ECHO) can underestimate the severity of disease. Exercise stress echocardiography (ESE) and the cardiopulmonary exercise testing (CPX) appeared to be useful tests in dynamic assessment of HFpEF. The value of combined exercise stress echocardiography cardiopulmonary testing (ESE-CPX) in the identification of masked HFpEF is still undetermined.

OBJECTIVE

The purpose of this study was to analyse the value of the combined ESE-CPX in the identification of masked HFpEF in patients with HTN, dyspnoea and normal resting left ventricular (LV) systolic and diastolic function.

METHODOLOGY

We studied 87 patients with HTN, exertional dyspnoea and normal resting LV function. They all underwent ESE-CPX testing (supine bicycle, ramp protocol, 15 W/min). ECHO measurements were performed at rest, and at peak load. Achievement of peak E/e' ratio>15 was a marker for masked HFpEF.

RESULTS

Increase of E/e'>15 occurred in 8/87 patients (9.2%) during ESE-CPX. Those patients had the lower peak VO2 (p = 0.012), the lower VO2 at anaerobic threshold (p = 0.025), the lower workload (p = 0.026), the lower peak partial pressure end tidal carbon dioxide (PetCO2) (p < 0.0001), and the higher VE/VCO2 slope (p < 0.0001) which was an independent multivariate predictor of HFpEF (p = 0.021), with the cut-off value of 32.95 according to the receiver-operator characteristic (ROC) curve (sensitivity (Sn) 100%, specificity (Sp) 90%).

CONCLUSION

The combined ESE-CPX test is feasible and reliable test that can unmask HFpEF and may become an important aid in the early diagnosis of HFpEF, excluding the other causes of exertional dyspnoea.

Endpoints in stem cell trials in ischemic heart failure

Despite multimodal regimens and diverse treatment options alleviating disease symptoms, morbidity and mortality associated with advanced ischemic heart failure remain high. Recently, technological innovation has led to the development of regenerative therapeutic interventions aimed at halting or reversing the vicious cycle of heart failure progression. Driven by the unmet patient need and fueled by encouraging experimental studies, stem cell-based clinical trials have been launched over the past decade. Collectively, these trials have enrolled several thousand patients and demonstrated the clinical feasibility and safety of cell-based interventions. However, the totality of evidence supporting their efficacy in ischemic heart failure remains limited. Experience from the early randomized stem cell clinical trials underscores the key points in trial design ranging from adequate hypothesis formulation to selection of the optimal patient population, cell type and delivery route. Importantly, to translate the unprecedented promise of regenerative biotherapies into clinical benefit, it is crucial to ensure the appropriate choice of endpoints along the regulatory path. Accordingly, we here provide considerations relevant to the choice of endpoints for regenerative clinical trials in the ischemic heart failure setting.

Time-dependent changes of plasma adiponectin concentration in relation to coronary microcirculatory function in patients with acute myocardial infarction treated by primary percutaneous coronary intervention

BACKGROUND AND PURPOSE

To analyze plasma adiponectin kinetics in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (pPCI) and its association with coronary flow reserve (CFR), an index of coronary microcirculatory function.

METHODS

A total of 96 consecutive patients with the first anterior STEMI treated by pPCI without heart failure were included. CFR was assessed on the 7th day after pPCI. Plasma adiponectin was measured on admission before pPCI, and on the 2nd and 7th day after pPCI.

RESULTS

Adiponectin concentration was the highest on admission, declined to the lowest level on the 2nd day, and rose on the 7th day remaining below admission values. Impaired coronary microcirculatory function (CFR<2) was observed in 41% of the patients. Adiponectin concentrations significantly positively correlated with CFR, and the strongest correlation was with the 2nd day adiponectin (r=0.489, p<0.001). In multivariate models, adiponectin concentrations were independent predictors of impaired CFR [on admission: odds ratio (OR) 0.175, confidence interval (CI): 0.047-0.654, p=0.010; 2nd day: OR 0.146, 95% CI: 0.044-0.485, p=0.002; 7th day: OR 0.198, CI: 0.064-0.611, p=0.005]. The best power to predict impaired CFR was the 2nd day adiponectin. Delta values of adiponectin (differences between adiponectin concentrations) did not correlate with CFR.

CONCLUSIONS

In patients with the first anterior STEMI treated by pPCI plasma adiponectin concentrations before and after pPCI are strongly associated with CFR. Our results support the hypothesis that low adiponectin, especially during the early post-pPCI period, carries the risk for impaired coronary microcirculatory function in STEMI patients.

Acute insulin resistance in ST-segment elevation myocardial infarction in non-diabetic patients is associated with incomplete myocardial reperfusion and impaired coronary microcirculatory function

Background

Insulin resistance (IR) assessed by the Homeostatic Model Assessment (HOMA) index in the acute phase of myocardial infarction in non-diabetic patients was recently established as an independent predictor of intrahospital mortality. In this study we postulated that acute IR is a dynamic phenomenon associated with the development of myocardial and microvascular injury and larger final infarct size in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (pPCI).

Methods

In 104 consecutive patients with the first anterior STEMI without diabetes, the HOMA index was determined on the 2^nd and 7^th day after pPCI. Worst-lead residual ST-segment elevation (ST-E) on postprocedural ECG, coronary flow reserve (CFR) determined by transthoracic Doppler echocardiography on the 2^nd day after pPCI and fixed perfusion defect on single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) determined six weeks after pPCI were analyzed according to HOMA indices.

Results

IR was present in 55 % and 58 % of patients on day 2 and day 7, respectively. Incomplete post-procedural ST-E resolution was more frequent in patients with IR compared to patients without IR, both on day 2 (p = 0.001) and day 7 (p < 0.001). The HOMA index on day 7 correlated with SPECT-MPI perfusion defect (r = 0.331), whereas both HOMA indices correlated well with CFR (r = -0.331 to -0.386) (p < 0.01 for all). In multivariable backward logistic regression analysis adjusted for significant univariate predictors and potential confounding variables, IR on day 2 was an independent predictor of residual ST-E ≥ 2 mm (OR 11.70, 95% CI 2.46-55.51, p = 0.002) and CFR < 2 (OR = 5.98, 95% CI 1.88-19.03, p = 0.002), whereas IR on day 7 was an independent predictor of SPECT-MPI perfusion defect > 20% (OR 11.37, 95% CI 1.34-96.21, p = 0.026).

Conclusion

IR assessed by the HOMA index during the acute phase of the first anterior STEMI in patients without diabetes treated by pPCI is independently associated with poorer myocardial reperfusion, impaired coronary microcirculatory function and potentially with larger final infarct size.