The Impact of Sex Differences on Fractional Flow Reserve–Guided Percutaneous Coronary Intervention

Sex Differences in Adenosine-Free Coronary Pressure Indexes: A CONTRAST Substudy

OBJECTIVES

The goal of this study was to investigate sex differences in adenosine-free coronary pressure indexes.

BACKGROUND

Several adenosine-free coronary pressure wire indexes have been proposed to assess the functional significance of coronary artery lesions; however, there is a theoretical concern that sex differences may affect diagnostic performance because of differences in resting flow and distal myocardial mass.

METHODS

In this CONTRAST (Can Contrast Injection Better Approximate FFR Compared to Pure Resting Physiology?) substudy, contrast fractional flow reserve (cFFR), obtained during contrast-induced submaximal hyperemia, the instantaneous wave-free ratio (iFR), and distal/proximal coronary pressure ratio (Pd/Pa) were compared with fractional flow reserve (FFR) in 547 men and 216 women. Using FFR ≤0.8 as a reference, the diagnostic performance of each index was compared.

RESULTS

Men and women had similar diameter stenosis (p = 0.78), but women were less likely to have FFR ≤0.80 than men (42.5% vs. 51.5%, p = 0.04). Sensitivity was similar among cFFR, iFR, and Pd/Pa when comparing women and men, respectively (cFFR, 77.5% vs. 75.3%; p = 0.69; iFR, 84.9% vs. 79.4%; p = 0.30; Pd/Pa, 78.8% vs. 77.3%; p = 0.78). cFFR was more specific than iFR or Pd/Pa regardless of sex (cFFR, 94.3% vs. 95.8%; p = 0.56; iFR, 75.6% vs. 80.1%; p = 0.38; Pd/Pa, 80.6% vs. 78.7%; p = 0.69). By receiver-operating characteristic curve analysis, cFFR provided better diagnostic accuracy than resting indexes irrespective of sex (p ≤ 0.0001).

CONCLUSIONS

Despite the theoretical concern, the diagnostic sensitivity and specificity of cFFR, iFR, and Pd/Pa did not differ between the sexes. Irrespective of sex, cFFR provides the best diagnostic performance.

Stable Ischemic Heart Disease in Women

PURPOSE OF THE REVIEW

Paradoxically, although women have a lower burden of coronary atherosclerosis, they experience more symptoms, more frequent hospitalizations, and a worse prognosis compared to men. This is in part due to biological variations in pathophysiology between the two sexes, and in part related to inadequate understanding of these differences, subconscious referral bias, and suboptimal application of existing women-specific guidelines. We sought to review the contemporary literature and provide an update on risk assessment, diagnosis, and management of IHD in women.

RECENT FINDINGS

IHD in women is often secondary to diffuse non-obstructive atherosclerosis, coronary spasm, inflammation, and endothelial and microvascular dysfunction, and less commonly due to the male pattern of flow-limiting epicardial stenosis. Both IHD patterns likely represent sex-specific manifestations of the same disease process. Additionally, there is a differential expression of risk factors and symptoms between men and women. Application of male-pattern IHD risk factors and presentation to women contributes to under-recognition, under-testing, and under-treatment of IHD in women compared to men. Traditional diagnostic evaluation has focused on detection of epicardial disease, amenable to revascularization. Our improved understanding of sex-specific pathophysiology of IHD has enabled us to also develop tools for detection of microvascular disease. Advances in stress MRI, flow quantification on stress PET, and provocative invasive angiography have filled this void and offer important diagnostic and prognostic information. Despite our improved understanding of sex-specific differences in presentation, risk factors, pathophysiology, diagnostic testing, and management strategies of IHD, women with IHD continue to experience worse outcomes than men. This disparity underscores the need for improved research and understanding of biological sex differences, elimination of subconscious gender bias in referral patterns, and improved application of existing research into clinical practice.

Frequency of abnormal fractional flow reserve measurements among major coronary arteries

BACKGROUND

Fractional flow reserve(FFR) is a validated tool for evaluating functional severity and guiding the revascularization of angiographically moderate coronary artery lesions.

OBJECTIVE

To study if there is a higher frequency of positive FFR measurements in the left anterior descending(LAD) versus other major coronary arteries and also evaluate the differences in the total length of the stent placed.

METHODS

A retrospective cohort study including all subjects (January 2011 to December 2015) who had fractional flow reserve (FFR) measured during coronary catheterization was conducted. Coronary catheterizations with FFR at a single tertiary care center were reviewed and FFR ≤ 0.80 post adenosine was deemed positive. The differences in the baseline characteristics and the degree of stenosis were compared between the different vessel groups.

RESULTS

Of the 758 vessels included in the analysis, the majority were LAD(51.3%) followed by right coronary artery(RCA)(22.8%), Circumflex(22.2%), Left main(2.2%), and Ramus intermedius(1.5%). 25.1% of 758 vessels were FFR positive. The proportion of positive FFR were higher among LAD versus other vessels(33.2%vs.16.5%,p < 0.001), while no differences were noted between RCA and circumflex(p = 0.87) or other vessels excluding LAD(p = 0.69). Of 175 patients who received stents, no statistical difference was noted in the median[range] total length of the stent between LAD(22[9-64]) and the other coronary arteries (18[8-42])(p = 0.19). In patients with an FFR <0.75, we found that the stent length(median [range]) was significantly longer in LAD(28[9-42]) than the other coronary arteries(18[8-42])(p = 0.03).

CONCLUSION

In our study, FFR was almost twice as likely to be positive in the LAD when compared to other major coronary arteries. Furthermore, there was a trend towards FFR positive LAD lesions needing longer stents than other coronary arteries. This data should encourage operators to evaluate moderate, long lesions in the LAD with FFR, as they have a higher probability of functional significance.

Test Selection for Women with Suspected Stable Ischemic Heart Disease

Ischemic heart disease (IHD) is the leading cause of death and disability among women in the United States. Identifying IHD in women presenting with stable symptoms and stratifying their risk for an IHD event can be challenging for providers, with several different tests available. This article is meant to serve as a practical guide for clinicians treating women with potentially ischemic symptoms. Evidence and American Heart Association (AHA) recommendations regarding test selection are reviewed, with a focus on the information to be gained from each test. We outline suggested courses of action to be taken in the case of a positive or negative test. Regardless of the initial test result, clinicians should view a woman's symptom presentation as an opportunity to review and modify her risk of cardiovascular events.

Gender-Specific Differences in All-Cause Mortality Between Incomplete and Complete Revascularization in Patients With ST-Elevation Myocardial Infarction and Multi-Vessel Coronary Artery Disease

The best revascularization strategy (complete vs incomplete revascularization) in patients with ST-elevation myocardial infarction (STEMI) is still debated. The interaction between gender and revascularization strategy in patients with STEMI on all-cause mortality is uncertain. The aim of the present study was to evaluate gender-specific difference in all-cause mortality between incomplete and complete revascularization in patients with STEMI and multi-vessel coronary artery disease. The study population consisted of 375 men and 115 women with a first STEMI and multi-vessel coronary artery disease without cardiogenic shock at admission or left main stenosis. The 30-day and 5-year all-cause mortality was examined in patients categorized according to gender and revascularization strategy (incomplete and complete revascularization). Within the first 30 days, men and women with incomplete revascularization were associated with higher mortality rates compared with men with complete revascularization. However, the gender-strategy interaction variable was not independently associated with 30-day mortality after STEMI when corrected for baseline characteristics and angiographic features. Within the survivors of the first 30 days, men with incomplete revascularization (compared with men with complete revascularization) were independently associated with all-cause mortality during 5 years of follow-up (hazard ratios 3.07, 95% confidence interval 1.24;7.61, p = 0.016). In contrast, women with incomplete revascularization were not independently associated with 5-year all-cause mortality (hazard ratios 0.60, 95% confidence interval 0.14;2.51, p = 0.48). In conclusion, no gender-strategy differences occurred in all-cause mortality within 30 days after STEMI. However, in the survivors of the first 30 days, incomplete revascularization in men was independently associated with all-cause mortality during 5-year follow-up, but this was not the case in women.

The relationship between the basal coronary translesional pressure ratio and fractional flow reserve

AIM

Fractional flow reserve (FFR) allows for physiological definition of coronary lesion severity but requires induction of maximal coronary circulation hyperemia with administration of adenosine leading to coronary resistive vessel vasodilatation. However, the hyperemic response to adenosine, and therefore the calculation of FFR, may be affected by dysfunction of the coronary microvasculature. The aim was to define the relationship between basal P_d /P_a and FFR and identify lesion-independent predictors of the change in P_d /P_a with hyperemia.

METHODS AND RESULTS

One hundred and sixty-six consecutive patients undergoing FFR measurement were prospectively enrolled (mean age 62.6 ± 10.3 years, 27% females). Basal P_d /P_a , FFR, and delta P_d /P_a (difference between basal P_d /P_a and FFR) were recorded. Independent predictors of delta P_d /P_a included angiographic lesion severity, lesion length, gender, body mass index, and total cholesterol:HDL cholesterol ratio. The best basal P_d /P_a cutoff value to predict lesion physiological significance was 0.87 (positive predictive value of 100% for an FFR value ≤0.80) and the best cutoff for nonsignificance was 0.93 (negative predictive value of 98% for an FFR value >0.80).

CONCLUSION

The delta P_d /P_a may be affected by patient gender, body mass index, and cholesterol profile. A basal P_d /P_a value of ≥0.93 is highly predictive of an FFR >0.80. Conversely, a basal P_d /P_a value of ≤0.87 is highly predictive of an FFR ≤0.80. © 2017 Wiley Periodicals, Inc.

Fractional flow reserve and resting indices for coronary physiologic assessment: Practical guide, tips, and tricks

Physiologic assessment using fractional flow reserve (FFR) to guide percutaneous coronary interventions (PCI) has been demonstrated to improve clinical outcomes, compared to angiography-guided PCI. Recently, resting indices such as resting Pd/Pa, "instantaneous wave-free ratio", and contrast medium induced FFR have been evaluated for the assessment of the functional consequences of coronary lesions. Herein, we review and discuss the use of FFR and other indices for the functional assessment of coronary lesions. This review will cover theoretical aspects, as well as practical points and common pitfalls related to coronary physiological assessment. © 2017 Wiley Periodicals, Inc.

The influence of sex on microvascular function

A number of studies consistently report higher rates of all clinical outcomes including postinfarction mortality, need for repeat revascularization, and reinfarction in women with cardiovascular diseases than in men. As well, the gender gap in the prevalence of cardiovascular diseases decreases progressively with increasing age. Yet, the diagnosis and treatment of these diseases differ between genders and women remain underdiagnosed for coronary heart disease. In a recent retrospective analysis we showed that, along with vessel under study and age, gender is a determinant of adenosine responses during studies of fractional flow reserve, an effect that was probably due to differences in microvascular function and that influenced the interpretation of fractional flow reserve data. These data demonstrate that not only the clinical presentation is different, but also the diagnostic approach to coronary artery disease might differ between sexes.A gap still exists in the understanding of the mechanisms, awareness, and treatment of coronary artery disease in women, but also, as we show, in the application of diagnostic modalities that are well established in men.

Sex Differences in Fractional Flow Reserve-Guided Revascularization: A Nationwide Analysis

BACKGROUND

Women with coronary artery disease are less likely to be revascularized than men based on angiography alone. Recent studies have shown that female patients have higher fractional flow reserve (FFR) values for a given severity of coronary stenosis. However, gender differences in coronary revascularization rates following FFR assessment are unknown.

METHODS

The nationwide inpatient sample database was used to identify all patients who underwent FFR in the United States between January 2009 and December 2010. We used propensity score matching to compare revascularization rates and in-hospital outcomes among men and women undergoing FFR measurements.

RESULTS

Among 3712 patients who underwent FFR during the study period, 1235 matched pairs of men and women were identified. The overall revascularization rates were lower in women than men (40.1% vs. 52.8%, p < 0.01). Women were less likely to undergo either percutaneous (35.2% vs. 45.6%, p < 0.01) or surgical revascularization following FFR than men (5.2% vs. 7.4%, p = 0.03). Women had a nonsignificant trend toward higher in-hospital mortality (0.8% vs. 0.5%, p = 0.32) and significantly higher rates of access site hematoma formation (2.7% vs. 0.8%, p < 0.01) compared to men.

CONCLUSION

In conclusion, this large nationwide study reveals that coronary revascularization rates are significantly lower in women than in men even after functional assessment with FFR.

When should fractional flow reserve be performed to assess the significance of borderline coronary artery lesions: Derivation of a simplified scoring system

OBJECTIVES

To derive a simplified scoring system (SSS) that can assist in selecting patients who would benefit from the application of fractional flow reserve (FFR).

BACKGROUND

Angiographers base decisions to perform FFR on their interpretation of % diameter stenosis (DS), which is subject to variability. Recent studies have shown that the amount of myocardium at jeopardy is an important factor in determining the degree of hemodynamic compromise.

METHODS

We conducted a retrospective multivariable analysis to identify independent predictors of hemodynamic compromise in 289 patients with 317 coronary vessels undergoing FFR. A SSS was derived using the odds ratios as a weighted factor. The receiver operator characteristics curve was used to identify the optimal cutoff (≥3) to discern a functionally significant lesion (FFR≤0.8).

RESULTS

Male gender, left anterior descending artery apical wrap, disease proximal to lesion, minimal lumen diameter and % DS predicted abnormal FFR (≤0.8) and lesion location in the left circumflex predicted a normal FFR. Using a cutoff score of ≥3 on the SSS, a specificity of 90.4% (95% CI: 83.0-95.3) and a sensitivity of 38.0% (95% CI: 31.5-44.9) was generated with a positive predictive value of 89.0% (95% CI: 80.7%-94.6%) and negative predictive value of 41.6% (95% CI: 35.1%-48.3%).

CONCLUSIONS

The decision to use FFR should be based not only on the % DS but also the size of the myocardial mass jeopardized. A score of ≥3 on the SSS should prompt further investigation with a pressure wire.

Factors Associated With Errors in Visual Estimation of the Functional Significance of Coronary Lesions

INTRODUCTION AND 

OBJECTIVES

Visual angiographic assessment continues to be used when decisions are made on whether to revascularize ambiguous coronary lesions. Multiple factors, other than the degree of stenosis, have been associated with the functional significance of a coronary lesion. The aim of this study was to investigate the ability of interventionists to visually predict the functional significance of a coronary lesion and the clinical and angiographic characteristics associated with errors in prediction.

METHODS

We conducted a concordance study of the functional significance of coronary lesions predicted by experienced interventionists and fractional flow reserve values measured by intracoronary pressure wire in 665 intermediate lesions (40%-70% diameter stenosis) in 587 patients. We determined which factors were independently associated with errors in prediction.

RESULTS

There was disagreement between the predicted fractional flow reserve value of ≤ 0.80 and the observed value in 30.1% of the lesions (overestimation: 11.3%; underestimation, 18.8%). Stent location in an artery other than the anterior descending artery or in a bifurcation was associated with overestimation. Male sex, severe calcification, and a greater myocardial territory distal to the lesion were significantly associated with the functional significance of the underestimated lesion.

CONCLUSIONS

Even when taking into account angiographic and clinical characteristics, there is a high rate of disagreement between visual estimation and direct measurement of intermediate coronary stenosis in relation to its functional significance. Specific angiographic and clinical characteristics are associated with an increased tendency to overestimate or underestimate the significance of lesions.

Long-term outcome of intravascular ultrasound application in patients with moderate coronary lesions and grey-zone fractional flow reserve

OBJECTIVE

This study aimed to assess the long-term outcome of intravascular ultrasound (IVUS) application in patients with a fractional flow reserve (FFR) of 0.75-0.80.

BACKGROUND

Scientifically evaluating anatomical structures is vital because structure influences both physiological function and decision-making in moderate coronary lesions, especially for those with an FFR of 0.75-0.80.

MATERIALS AND METHODS

Patients (n=128) were divided into three groups based on treatment: the drug control group (n=40), the IVUS-percutaneous coronary intervention (PCI) group (n=40) and the IVUS-drug group (n=48). A PCI was performed when a patient had a minimum lumen area less than 4 mm(2) and a plaque burden of 70% or greater. Major adverse clinical events were defined as cardiac death, nonfatal myocardial infarction, target vessel revascularization, including PCI or coronary artery bypass grafting, and unstable angina, all of which were also evaluated during follow-up.

RESULTS

Kaplan-Meier curves indicated that the incidence of major adverse clinical events did not differ between the IVUS-PCI and IVUS-drug groups (5 vs. 6.3%, P=0.810), but the levels in both of these groups significantly decreased compared with the drug control group (5 vs. 22.5%, P=0.024, and 6.5 vs. 22.5%, P=0.026, respectively).

CONCLUSION

The long-term outcome of the application of IVUS in patients with a grey-zone FFR of 0.75-0.80 was superior to that of patients who were treated only with drugs without IVUS measurement. Patients with a grey-zone FFR should receive an individualized treatment strategy according to their IVUS parameters. Patients with the same FFR values may require different treatment strategies.

Fractional Flow Reserve Evaluation and Chronic Kidney Disease: Analysis From a Multicenter Italian Registry (the FREAK Study)

OBJECTIVES

To establish if the presence of chronic kidney disease (CKD) influences fractional flow reserve (FFR) value in patients with intermediate coronary stenosis.

BACKGROUND

FFR-guided coronary revascularization reduces cardiac adverse events in patients with coronary artery disease. CKD impairs microcirculation and increases cardiovascular risk. Whether CKD presence may limit FFR accuracy is unknown.

METHODS

We used data from a multicenter prospective registry enrolling 1.004 patients undergoing FFR evaluation for intermediate stenosis. We assessed the relationship between clinical and angiographic variables and FFR measurement. CKD was defined as CrCl value ≤45 ml/min. FFR value was considered potentially flow-limiting, and therefore positive, if ≤0.80. The index of microcirculatory resistance (IMR) was calculated in 20 patients stratified according CrCl value (single-center substudy).

RESULTS

FFR measurement was positive in 395 (39%) patients. Overall, 131 (13%) patients had CKD. Patients with CrCl ≤45 ml/min showed significantly higher FFR values as compared to the others (0.84 ± 0.07 vs. 0.81 ± 0.08, p < 0.001). Positive FFR occurrence was lower in patients with CrCl ≤45 ml/min (27% vs. 41%, p < 0.01). After multivariable analysis, diabetes (HR 1.07, 95%CI 1.008-1.13, p = 0.03), left anterior descending (HR 1.35, 95%CI 1.27-1.43, p < 0.001) and CrCl ≤45 ml/min (HR 0.92, 95%CI 0.87-0.97, p = 0.005) emerged as independent predictors of FFR measurement. Accordingly, IMR values were higher in patients with CrCl ≤45 ml/min (32 U [28245] vs. 16 U [11220], p < 0.01).

CONCLUSIONS

FFR and IMR measurements differ between CKD patients and those with normal renal function. Flow-limiting FFR is less frequent in patients with CrCl ≤45 ml/min. © 2015 Wiley Periodicals, Inc.

Atherosclerotic plaque characteristics by CT angiography identify coronary lesions that cause ischemia: a direct comparison to fractional flow reserve

OBJECTIVES

This study evaluated the association between atherosclerotic plaque characteristics (APCs) by coronary computed tomographic angiography (CTA), and lesion ischemia by fractional flow reserve (FFR).

BACKGROUND

FFR is the gold standard for determining lesion ischemia. Although APCs by CTA-including aggregate plaque volume % (%APV), positive remodeling (PR), low attenuation plaque (LAP), and spotty calcification (SC)-are associated with future coronary syndromes, their relationship to lesion ischemia is unclear.

METHODS

252 patients (17 centers, 5 countries; mean age 63 years; 71% males) underwent coronary CTA, with FFR performed for 407 coronary lesions. Coronary CTA was interpreted for <50% and ≥50% stenosis, with the latter considered obstructive. APCs by coronary CTA were defined as: 1) PR, lesion diameter/reference diameter >1.10; 2) LAP, any voxel <30 Hounsfield units; and 3) SC, nodular calcified plaque <3 mm. Odds ratios (OR) and net reclassification improvement of APCs for lesion ischemia, defined by FFR ≤0.8, were analyzed.

RESULTS

By FFR, ischemia was present in 151 lesions (37%). %APV was associated with a 50% increased risk of ischemia per 5% additional APV. PR, LAP, and SC were associated with ischemia, with a 3 to 5 times higher prevalence than in nonischemic lesions. In multivariable analyses, a stepwise increased risk of ischemia was observed for 1 (OR: 4.0, p < 0.001) and ≥2 (OR: 12.1, p < 0.001) APCs. These findings were APC dependent, with PR (OR: 5.3, p < 0.001) and LAP (OR: 2.1, p = 0.038) associated with ischemia, but not SC. When examined by stenosis severity, PR remained a predictor of ischemia for all lesions, whereas %APV and LAP were associated with ischemia for only ≥50%, but not for <50%, stenosis.

CONCLUSIONS

%APV and APCs by coronary CTA improve identification of coronary lesions that cause ischemia. PR is associated with all ischemia-causing lesions, whereas %APV and LAP are only associated with ischemia-causing lesions ≥50%. (Determination of Fractional Flow Reserve by Anatomic Computed Tomographic Angiography; NCT01233518).

Fractional flow reserve: physiological basis, advantages and limitations, and potential gender differences

Fractional flow reserve (FFR) is a physiological index of the severity of a stenosis in an epicardial coronary artery, based on the pressure differential across the stenosis. Clinicians are increasingly relying on this method because it is independent of baseline flow, relatively simple, and cost effective. The accurate measurement of FFR is predicated on maximal hyperemia being achieved by pharmacological dilation of the downstream resistance vessels (arterioles). When the stenosis causes FFR to be impaired by > 20%, it is considered to be significant and to justify revascularization. A diminished hyperemic response due to microvascular dysfunction can lead to a false normal FFR value, and a misguided clinical decision. The blunted vasodilation could be the result of defects in the signaling pathways modulated (activated or inhibited) by the drug. This might involve a downregulation or reduced number of vascular receptors, endothelial impairment, or an increased activity of an opposing vasoconstricting mechanism, such as the coronary sympathetic nerves or endothelin. There are data to suggest that microvascular dysfunction is more prevalent in post-menopausal women, perhaps due to reduced estrogen levels. The current review discusses the historical background and physiological basis for FFR, its advantages and limitations, and the phenomenon of microvascular dysfunction and its impact on FFR measurements. The question of whether it is warranted to apply gender-specific guidelines in interpreting FFR measurements is addressed.

The ischaemic constellation: an alternative to the ischaemic cascade-implications for the validation of new ischaemic tests

The ischaemic cascade is the concept that progressive myocardial oxygen supply-demand mismatch causes a consistent sequence of events, starting with metabolic alterations and followed sequentially by myocardial perfusion abnormalities, wall motion abnormalities, ECG changes, and angina. This concept would suggest that investigations that detect expressions of ischaemia earlier in the cascade should be more sensitive tests of ischaemia than those that detect expressions appearing later in the cascade. However, careful review of the studies on which the ischaemic cascade is based suggests that the ischaemic cascade concept may be less well supported by the literature than assumed. In this review we explore this, discuss an alternative method for conceptualising ischaemia, and discuss the potential implications of this new approach to clinical studies and clinical practice.

Diagnostic accuracy and discrimination of ischemia by fractional flow reserve CT using a clinical use rule: results from the Determination of Fractional Flow Reserve by Anatomic Computed Tomographic Angiography study

BACKGROUND

Fractional flow reserve (FFR) is the gold standard for determining lesion-specific ischemia. Computed FFRCT derived from coronary CT angiography (coronary CTA) correlates well with invasive FFR and accurately differentiates between ischemia-producing and nonischemic lesions. The diagnostic performance of FFRCT when applied in a clinically relevant way to all vessels ≥ 2 mm in diameter stratified by sex and age has not been previously examined.

METHODS

Two hundred fifty-two patients and 407 vessels underwent coronary CTA, FFRCT, invasive coronary angiography, and invasive FFR. FFRCT and FFR ≤ 0.80 were considered ischemic, whereas CT stenosis ≥ 50% was considered obstructive. The diagnostic performance of FFRCT was assessed following a prespecified clinical use rule which included all vessels ≥ 2 mm in diameter, not just those assessed by invasive FFR measurements. Stenoses <30% were assigned an FFR of 0.90, and stenoses >90% were assigned an FFR of 0.50. Diagnostic performance of FFRCT was stratified by vessel diameter, sex, and age.

RESULTS

By FFR, ischemia was identified in 129 of 252 patients (51%) and in 151 of 407 vessels (31%). Mean age (± standard deviation) was 62.9 ± 9 years, and women were older (65.5 vs 61.9 years; P = .003). Per-patient diagnostic accuracy (83% vs 72%; P < .005) and specificity (54% vs 82%, P < .001) improved significantly after application of the clinical use tool. These were significantly improved over standard coronary CTA values before application of the clinical use rule. Discriminatory power of FFRCT also increased compared with baseline (area under the receiver operating characteristics curve [AUC]: 0.93 vs 0.81, P < .001). Diagnostic performance improved in both sexes with no significant differences between the sexes (AUC: 0.93 vs 0.90, P = .43). There were no differences in the discrimination of FFRCT after application of the clinical use rule when stratified by age ≥ 65 or <65 years (AUC: 0.95 vs 0.90, P = .10).

CONCLUSIONS

The diagnostic accuracy and discriminatory power of FFRCT improve significantly after the application of a clinical use rule which includes all clinically relevant vessels >2 mm in diameter. FFRCT has similar diagnostic accuracy and discriminatory power for ischemia detection in men and women irrespective of age using a cut point of 65 years.

Characteristics of function-anatomy mismatch in patients with coronary artery disease

Background and Objectives

Coronary lesions with mismatched functional and anatomical significance are not uncommon. We assessed the accuracy and predictors of mismatch between fractional flow reserve (FFR) and quantitative coronary angiography (QCA) analyses in patients with coronary lesions.

Subjects and Methods

A total of 643 lesions with pre-interventional FFR and QCA measurements were consecutively enrolled and divided into four groups using FFR ≤0.80 and percent diameter stenosis (%DS) ≥50% as cutoffs for functional and anatomical significance, respectively. Accordingly, FFR >0.80 and DS ≥50%, and FFR ≤0.80 and DS <50% defined false-positive (FP) and false-negative (FN) lesions, respectively.

Results

Overall, 40.4% (260/643) of the lesions were mismatched, and 51.7% (218/414) and 18.3% (42/229) were FP and FN lesions, respectively. In a multivariate analysis, independent predictors of FP were non-left anterior descending artery location {odds ratio (OR), 0.36; 95% confidence interval (CI), 0.28-0.56; p<0.001}, shorter lesion length (OR, 0.96; 95% CI, 0.95-0.98; p<0.001), multi-vessel disease (OR, 0.47; 95% CI, 0.30-0.75; p=0.001), and larger minimal lumen diameter by QCA (OR, 2.88; 95% CI,1.65-5.00; p<0.001). Independent predictors of FN were multi-vessel disease (OR, 1.82; 95% CI, 1.24-5.27; p=0.048), aging (OR, 0.96; 95% CI, 0.93-0.99; p=0.034), smoking (OR, 0.36; 95% CI, 0.14-0.93; p=0.034), and smaller reference vessel diameter by QCA (OR, 0.30; 95% CI, 0.10-0.87; p=0.026).

Conclusion

A mismatch between FFR and angiographic lesion severity is not rare in patients with coronary artery disease; therefore, an angiography-guided evaluation could under- or over-estimate lesion severity in specific lesion subsets.

The impact of gender on fractional flow reserve measurements

AIMS

Fractional flow reserve (FFR) allows accurate investigation of the functional significance of intermediate coronary stenoses. The present study set out to study the impact of gender on FFR measurements.

METHODS AND RESULTS

Three hundred and seventeen intermediate (40-70% at angiography) stenoses were assessed with FFR in 270 patients (mean age 65.8 ± 10.3 years, 84 females). Resting Pd/Pa (the ratio of mean blood pressure measured distal to the stenosis to mean aortic blood pressure in resting conditions), FFR (Pd/Pa during adenosine-induced hyperaemia) and the ΔPd/Pa (calculated as the change in Pd/Pa during hyperaemia) were measured. There was no difference in the location and degree of stenoses between genders (p>0.5). Similarly, there was no difference in age and in the prevalence of cardiovascular risk factors (all p>0.2). Resting Pd/Pa also did not differ between genders (0.92 ± 0.08 vs. 0.93 ± 0.05, p=0.23). In response to adenosine, however, a significantly larger ΔPd/Pa (0.14 ± 0.07 vs. 0.11 ± 0.07, p=0.001) and a significantly lower FFR (0.79 ± 0.12 vs. 0.82 ± 0.10, p=0.008) were observed in males. This difference was maintained in a multivariate regression analysis.

CONCLUSIONS

We observed gender-based differences in FFR data in daily routine. Further studies are necessary to test the mechanism of this observation and how these differences impact on the assessment of haemodynamically relevant stenoses.

Sex differences in the visual-functional mismatch between coronary angiography or intravascular ultrasound versus fractional flow reserve

OBJECTIVES

This study sought to assess differences in visual-functional mismatches between men and women.

BACKGROUND

Sex differences in mismatch between coronary anatomy and function remain poorly understood.

METHODS

We assessed quantitative coronary angiography, intravascular ultrasound (IVUS), fractional flow reserve (FFR), and echocardiographic left ventricular mass in a prospective cohort of 700 patients (493 male and 207 female patients) with 700 left anterior descending coronary lesions.

RESULTS

The female patients were older than the male patients (64 ± 10 years vs. 60 ± 10 years, p < 0.001) and body surface area (BSA) (57 ± 0.13 m(2) vs. 1.79 ± 0.13 m(2), p < 0.001) and left ventricular mass (151 ± 37g vs. 171 ± 41 g, p < 0.001) were smaller. Although there were no sex differences in angiographic diameter stenosis, lesion length, and IVUS minimal lumen area (MLA), FFR was higher in female patients (0.83 ± 0.09 vs. 0.79 ± 0.09, p < 0.001). Female patients had a smaller reference vessel area (11.4 ± 3.3 mm(2) vs. 13.1 ± 4.0 mm(2)), vessel area (9.0 ± 3.3 mm(2) vs. 11.1 ± 4.2 mm(2)), and plaque burden (69.8 ± 13.7% vs. 73.8 ± 12.2%) at the MLA site compared with male patients (all p < 0.001). To predict FFR <0.80, angiography had a lower positive predictive value in female patients (44% vs. 60%, p = 0.014); this was also seen in the IVUS analysis. Unlike angiography, the IVUS-MLA had a lower concordance rate in female patients (64% vs. 71%, p = 0.046). Independent predictors of FFR were age, BSA, lesion length, angiographic diameter stenosis, and IVUS-MLA and plaque burden. When left ventricular mass was included, it also predicted FFR, replacing BSA.

CONCLUSIONS

In female patients with smaller BSA, left ventricular mass, and vessel size, smaller myocardial territory may be responsible for the higher FFR value for any given stenosis compared with male patients. Considering the higher rate of visual-functional mismatch, FFR-guided decision making is especially important in female patients to avoid unnecessary procedures. (Natural History of FFR-Guided Deferred Coronary Lesions [IRIS FFR-DEFER Registry]; NCT01366404).

Sex-related differences in fractional flow reserve-guided treatment

BACKGROUND

Sex-specific differences affect the evaluation, treatment, and prognosis of coronary artery disease. We tested the hypothesis that long-term outcomes of fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) are different between women and men.

METHODS AND RESULTS

Consecutive 1090 patients, referred for PCI and undergoing FFR measurements at the Mayo Clinic between October 2002 and December 2009, were included in this registry study. Clinical events were compared between the sexes during a median follow-up of 50.9 months. Of all patients, women had higher FFR adjusted by visual coronary stenosis than men (P=0.03). The Kaplan-Meier percent of major adverse cardiac events at 5 years was 35% in women and 38% in men (P=0.54). Interestingly, in patients undergoing PCI with an FFR <0.75, the incidence of death or myocardial infarction was significantly higher in women than in men (hazard ratio, 2.16; 95% confidence interval, 1.04-4.51; P=0.04). Moreover, compared with patients with FFR >0.80, deferral of PCI for those with FFR between 0.75 and 0.80 was associated with an increased rate of major adverse cardiac events, particularly death or myocardial infarction in women (hazard ratio, 3.25; 95% confidence interval, 1.56-6.74; P=0.002) and revascularization in men (hazard ratio, 2.66; 95% confidence interval, 1.66-4.54; P<0.001).

CONCLUSIONS

Long-term outcome differs between women and men undergoing FFR-guided PCI. Our data suggest that the sex-based treatment strategy is necessary to further optimize prognosis of patients with coronary artery disease.

Detection of gender differences in incomplete revascularization after coronary artery bypass surgery varies with classification technique

Background. Incomplete revascularization negatively affects survival after coronary artery bypass surgery (CABG). Since gender and classification technique might impact outcome and reporting, we investigated their effect on revascularization patterns and mortality. Methods. A cohort of bypass patients (N = 1545, 23% women) was enrolled prospectively. The degree of revascularization was determined as mathematical difference between affected vessels upon diagnosis and number of grafts or the surgeon's rating on the case file. Results. Although men displayed more triple-vessel disease, they obtained complete revascularization more frequently than women (85% versus 77%, P < 0.001). The two calculation methods identified analogous percentages of incompletely revascularized patients, yet there was only a 50% overlap between the two groups. Mathematically, more women, older patients, and patients with NYHA class III/IV appeared incompletely revascularized, while the surgeons identified more patients undergoing technically challenging procedures. Regardless of the definition, incompleteness was a significant risk factor for mortality in both genders (mathematical calculation: HR 2.62, 95% CI 1.76–3.89, P < 0.001; surgeon: HR 2.04, 95% CI 1.35–3.89, P = 0.001). Conclusions. Given the differences in identification patterns, we advise that the mathematical calculation be performed after-procedure in all patients regardless of the surgeons' rating to uncover additional subjects at increased risk.

Diagnosing and characterizing coronary artery disease in women: developments in noninvasive and invasive imaging techniques

Cardiovascular disease is the leading cause of death in men and women in the USA; yet, coronary artery disease (CAD) continues to be underrecognized and underdiagnosed in women. Noninvasive and invasive imaging techniques are constantly being developed in order to more accurately assess CAD. At the same time, the impact of gender on the interpretation and accuracy of these studies is still being elucidated. Furthermore, new imaging techniques have improved our understanding of CAD pathophysiology and progression and have begun to reveal gender differences in the development of CAD. This article will review current imaging techniques and their application to diagnosing and understanding CAD in women.