What Do We Know about Peripartum Cardiomyopathy? Yesterday, Today, Tomorrow.

Peripartum cardiomyopathy is a disease that occurs during or after pregnancy and leads to a significant decline in cardiac function in previously healthy women. Peripartum cardiomyopathy has a varying prevalence among women depending on the part of the world where they live, but it is associated with a significant mortality and morbidity in this population. Therefore, timely diagnosis, treatment, and monitoring of this disease from its onset are of utmost importance. Although many risk factors are associated with the occurrence of peripartum cardiomyopathy, such as conditions of life, age of the woman, nutrient deficiencies, or multiple pregnancies, the exact cause of its onset remains unknown. Advances in research on the genetic associations with cardiomyopathies have provided a wealth of data indicating a possible association with peripartum cardiomyopathy, but due to numerous mutations and data inconsistencies, the exact connection remains unclear. Significant insights into the pathophysiological mechanisms underlying peripartum cardiomyopathy have been provided by the theory of an abnormal 16-kDa prolactin, which may be generated in an oxidative stress environment and lead to vascular and consequently myocardial damage. Recent studies supporting this disease mechanism also include research on the efficacy of bromocriptine (a prolactin synthesis inhibitor) in restoring cardiac function in affected patients. Despite significant progress in the research of this disease, there are still insufficient data on the safety of use of certain drugs treating heart failure during pregnancy and breastfeeding. Considering the metabolic changes that occur in different stages of pregnancy and the postpartum period, determining the correct dosing regimen of medications is of utmost importance not only for better treatment and survival of mothers but also for reducing the risk of toxic effects on the fetus.

Prognostic Value of Mitral Regurgitation in Patients with Primary Hypertrophic Cardiomyopathy.

Background and Objectives: Mitral valve pathology and mitral regurgitation (MR) are very common in patients with hypertrophic cardiomyopathy (HCM), and the evaluation of mitral valve anatomy and degree of MR is important in patients with HCM. The aim of our study was to examine the potential influence of moderate or moderately severe MR on the prognosis, clinical presentation, and structural characteristics of HCM patients. Materials and Methods: A prospective study examined 176 patients diagnosed with primary asymmetric HCM. According to the severity of the MR, the patients were divided into two groups: Group 1 (n = 116) with no/trace or mild MR and Group 2 (n = 60) with moderate or moderately severe MR. All patients had clinical and echocardiographic examinations, as well as a 24 h Holter ECG. Results: Group 2 had significantly more often the presence of the obstructive type of HCM (p < 0.001), syncope (p = 0.030), NYHA II class (p < 0.001), and atrial fibrillation (p = 0.023). Also, Group 2 had an enlarged left atrial dimension (p < 0.001), left atrial volume index (p < 0.001), and indirectly measured systolic pressure in the right ventricle (p < 0.001). Patients with a higher grade of MR had a significantly higher E/e' (p < 0.001) and, as a result, higher values of Nt pro BNP values (p < 0.001) compared to Group 1. Kaplan-Meier analysis demonstrated that the event-free survival rate during a median follow-up of 88 (IQR 40-112) months was significantly higher in Group 1 compared to Group 2 (84% vs. 45% at 8 years; log-rank 20.4, p < 0.001). After adjustment for relevant confounders, the presence of moderate or moderately severe MR remained as an independent predictor of adverse outcomes (HR 2.788; 95% CI 1.221-6.364, p = 0.015). Conclusions: The presence of moderate or moderately severe MR was associated with unfavorable long-term outcomes in HCM patients.

Randomized Controlled Comparison of Optimal Medical Therapy with Percutaneous Recanalization of Chronic Total Occlusion (COMET-CTO).

The aim of this randomized prospective study was to evaluate the quality of life (QoL) using the "Seattle Angina Questionnaire" (SAQ) in patients with chronic total occlusion (CTO) in coronary arteries treated with either percutaneous coronary intervention (PCI) or optimal medical therapy (OMT), or only with OMT.The potential benefits of recanalization of CTO by PCI have been controversial because of the scarcity of randomized controlled trials.A total of 100 patients with CTO were randomized (1:1) prospectively into the PCI CTO or the OMT group (50 patients in each group). There were no baseline differences in the SAQ scores between the groups, except for physical limitation scores (P = 0.03). During the mean follow-up (FUP) of 275 ± 88 days, patients in the PCI group reported less physical activity limitations (72.7 ± 21.3 versus 60.5 ± 27, P = 0.014), less frequent angina episodes (89.8 ± 17.6 versus 76.8 ± 27.1, P = 0.006), better QoL (79.9 ± 22.7 versus 62.5 ± 25.5, P = 0.001), greater treatment satisfaction (91.2 ± 13.6 versus 81.4 ± 18.4, P = 0.003), and borderline differences in angina stability (61.2 ± 26.5 versus 51.0 ± 23.7, P = 0.046) compared to patients in the OMT group. There were no significant differences in SAQ scores in the OMT group at baseline and during the FUP. There was a statistically significant increase in all five domains in the PCI group.Symptoms and QoL measured by the SAQ were significantly improved after CTO PCI compared to OMT alone.

Prompt and consistent improvement of coronary flow velocity reserve following successful recanalization of the coronary chronic total occlusion in patients with viable myocardium.

BACKGROUND: Coronary chronic total occlusion (CTO) is characterized by the presence of collateral blood vessels which can provide additional blood supply to CTO-artery dependent myocardium. Successful CTO recanalization is followed by significant decrease in collateral donor artery blood flow and collateral derecruitment, but data on coronary hemodynamic changes in relation to myocardial function are limited. We assessed changes in coronary flow velocity reserve (CFVR) by echocardiography in collateral donor and recanalized artery following successful opening of coronary CTO. METHODS: Our study enrolled 31 patients (60 ± 9 years; 22 male) with CTO and viable myocardium by SPECT scheduled for percutaneous coronary intervention (PCI). Non-invasive CFVR was measured in collateral donor artery before PCI, 24 h and 6 months post-PCI, and 24 h and 6 months in recanalized artery following successful PCI of CTO. RESULTS: Collateral donor artery showed significant increase in CFVR 24 h after CTO recanalization compared to pre-PCI values (2.30 ± 0.49 vs. 2.71 ± 0.45, p = 0.005), which remained unchanged after 6-months (2.68 ± 0.24). Baseline blood flow velocity of the collateral donor artery significantly decreased 24 h post-PCI compared to pre-PCI (0.28 ± 0.06 vs. 0.24 ± 0.04 m/s), and remained similar after 6 months, with no significant difference in maximum hyperemic blood flow velocity pre-PCI, 24 h and 6 months post-PCI. CFVR of the recanalized coronary artery 24 h post-PCI was 2.55 ± 0.35, and remained similar 6 months later (2.62 ± 0.26, p = NS). CONCLUSIONS: In patients with viable myocardium, prompt and significant CFVR increase in both recanalized and collateral donor artery, was observed within 24 h after successful recanalization of CTO artery, which maintained constant during the 6 months. TRIAL REGISTRATION: ClinicalTrials.gov (Number NCT04060615 ).

Improved Propensity-Score Matched Long-Term Clinical Outcomes in Patients with Successful Percutaneous Coronary Interventions of Coronary Chronic Total Occlusion.

The objective of the study was to evaluate major adverse cardiovascular events (MACE) after successful versus failed percutaneous coronary intervention for chronic total occlusion (PCI-CTO).Limited data are available on long-term clinical follow-up in the treatment of chronic total occlusion (CTO).Between January 2009 and December 2010 PCI-CTO was attempted in 283 consecutive patients with 289 CTO lesions. Procedural success was 62.3% and clinical follow-up covered 83% (235/283) of the study population with a median follow-up of 66 months (range, 59-74).The total incidence of MACE was 57/235 (24.3%), and was significantly higher in the procedural failure group than in the procedural success group (33/87 (37.9%) versus 24/148 (16.2%), P < 0.001). All-cause mortality was significantly lower in patients with successful PCI-CTO compared to failed PCI-CTO (10.8% versus 20.7%, P < 0.05). Also, the rate of cardiovascular death in the procedural failure group (14.9%) was slightly higher than that in the procedural success group (7.4%, P = 0.066). The rate of TVR was statistically higher in the procedural failure group (P < 0.009). Propensity score-adjusted Cox regression showed that procedural success remained a significant predictor of MACE (adjusted HR 0.402; 95% CI 0.196-0.824; P = 0.013).Our study emphasizes the importance of CTO recanalization in improving long-term outcome including all-cause mortality with a borderline effect on cardiovascular mortality.

Diagnosis and treatment of angiographically unclear coronary lesions.

Although selective coronary angiography is the gold standard diagnostic technique for coronary lesions, this method does not provide all information regarding pathophysiologic mechanisms. We herein describe a patient in their early 60s with a 3-month history of pronounced angina. Coronary angiography revealed a central line of illumination in the proximomedial segment of the right coronary artery, suggesting a chronic coronary dissection/recanalized thrombus, along with positive remodeling and TIMI grade 2 flow. Optical coherence tomography showed a recanalized thrombus and multiple lumens separated by thin septa. Because of the significantly reduced flow and signs of ischemia in the right coronary artery irrigation territory, we decided to perform percutaneous coronary intervention. Post-treatment optical coherence tomography indicated optimal apposition and expansion of the stents with positive remodeling of the blood vessel. We believe that decisions regarding treatment modalities should be guided by the presence or absence of ischemia. Lesions that are causing myocardial ischemia should be revascularized; otherwise, medical treatment can be utilized.

Correlation of Non-Invasive Transthoracic Doppler Echocardiography with Invasive Doppler Wire-Derived Coronary Flow Reserve and Their Impact on Infarct Size in Patients with ST-Segment Elevation Myocardial Infarction Treated with Primary Percutaneous Coronary Intervention.

Background: Coronary microvascular dysfunction is associated with adverse prognosis after ST-segment elevation myocardial infarction (STEMI). We aimed to compare the invasive, Doppler wire-based coronary flow reserve (CFR) with the non-invasive transthoracic Doppler echocardiography (TTDE)-derived CFR, and their ability to predict infarct size. Methods: We included 36 patients with invasive Doppler wire assessment on days 3-7 after STEMI treated with primary percutaneous coronary intervention (PCI), of which TTDE-derived CFR was measured in 47 vessels (29 patients) within 6 h of the invasive Doppler. Infarct size was assessed by cardiac magnetic resonance at a median of 8 months. Results: The correlation between invasive and non-invasive CFR was modest in the overall cohort (rho 0.400, p = 0.005). It improved when only measurements in the LAD artery were considered (rho 0.554, p = 0.002), with no significant correlation in the RCA artery (rho -0.190, p = 0.435). Both invasive (AUC 0.888) and non-invasive (AUC 0.868) CFR, measured in the recanalized culprit artery, showed a good ability to predict infarct sizes ≥18% of the left ventricular mass, with the optimal cut off values of 1.85 and 1.80, respectively. Conclusions: In patients with STEMI, TTDE- and Doppler wire-derived CFR exhibit significant correlation, when measured in the LAD artery, and both have a similarly strong association with the final infarct size.

Association of Successful Percutaneous Revascularization of Chronic Total Occlusions With Quality of Life: A Systematic Review and Meta-Analysis.

Importance: Chronic total occlusion percutaneous coronary intervention (CTO-PCI) is not usually offered because of skepticism about long-term clinical benefits. Objective: To assess the association of successful CTO-PCI with quality of life by analyzing the relevant domains of the Seattle Angina Questionnaire (SAQ). Data Sources: PubMed, EMBASE, Web of Science, Google Scholar, and Cochrane databases were searched to identify randomized trials and observational studies specifically addressing quality of life domains of SAQ from January 2010 to June 2022. Study Selection: Studies included reporting SAQ metrics such as angina frequency, physical limitation, and quality of life, before and after CTO-PCI. Data Extraction and Synthesis: The present study was performed according to the Cochrane Collaboration and Preferred Reporting Items for Systematic Reviews and Meta-Analyses statements, in which fixed-effect or random-effect models with generic inverse-variance weighting depending on statistical homogeneity were applied. Data were extracted by 3 independent reviewers. Outcomes and Measures: The primary outcome was angina frequency; physical limitation and quality of life were assessed as secondary outcomes. Results: Seven prospective randomized or observational studies (2500 patients) were included, with a mean (SD) participant age of 61.2 (2.1) years. CTO-PCI was associated with significantly improved quality-of-life metrics during a mean (SD) follow-up of 14.8 (16.3) months. In patients with successful procedures, angina episodes became less frequent (mean [SD] difference for SAQ angina frequency of 12.9 [3.1] survey points [95% CI, 7.1-19.8 survey points]; standardized mean difference was 0.54 [95% CI, 0.21-0.92]; P = .002; I2 = 86.4%) and they experienced less physical activity limitation (mean [SD] difference for SAQ physical limitation of 9.7 [6.2] survey points [95% CI, 3.5-16.2 survey points]; standardized mean difference was 0.42 [95% CI, 0.24-0.55]; P < .001; I2 = 20.9%), and greater quality-of-life domain (mean [SD] difference for SAQ quality of life of 14.9 [3.5] survey points [95% CI, 7.7-22.5 survey points]; standardized mean difference was 0.41 [95% CI, 0.25-0.61]; P < .001; I2 = 58.8%) compared with patients with optimal medical therapy or failed procedure. Furthermore, follow-up duration (point estimate, 0.03; 95% CI, 0.01-0.04; P = .01) was associated with a significant decrease in angina frequency in meta-regression analysis. Conclusions and Relevance: In this systematic review and meta-analysis examining quality of life following CTO-PCI, successful procedures were associated with improved quality-of-life parameters compared with patients on optimal medical therapy or after failed CTO-PCI. These findings suggest support for using PCI to treat CTOs in symptomatic patients unresponsive to medical treatment.

An analysis of published cases of cutting balloon use in spontaneous coronary artery dissection.

Introduction: SCAD involves a sudden tear or separation within the layers of the coronary artery wall, resulting in blood flow obstruction and subsequent myocardial ischemia. Materials and methods: A comprehensive literature search was conducted to identify relevant published cases of cutting balloon use in patients diagnosed with spontaneous coronary artery dissection. Electronic databases including PubMed, MEDLINE, Embase, Cochrane Library and Google Scholar were systematically searched from inception until the present using terms "cutting balloon," "SCAD," "acute coronary syndrome," "intramural hematoma," and "angioplasty." Results: A total of 32 published cases of cutting balloon use in spontaneous coronary artery dissection were analyzed in this study. The majority of the patients included in the analysis were female without prior history of cardiovascular disease. The median age of the SCAD population was approximately 46 years. The most frequently affected artery in SCAD cases was the Left Anterior Descending artery. Intravascular ultrasound was utilized more frequently than other modalities of adjunctive imaging techniques. The most frequent complication was the distal propagation of hematoma. Despite the successful dilation achieved with the cutting balloon, in some cases stenting was required to provide additional support. Conclusion: The results of this analysis demonstrate that cutting balloon use in SCAD cases yields favorable outcomes.

Current status and future perspectives of fractional flow reserve derived from invasive coronary angiography.

Assessment of the functional significance of coronary artery stenosis using invasive measurement of fractional flow reserve (FFR) or non-hyperemic indices has been shown to be safe and effective in making clinical decisions on whether to perform percutaneous coronary intervention (PCI). Despite strong evidence from clinical trials, utilization of these techniques is still relatively low worldwide. This may be to some extent attributed to factors that are inherent to invasive measurements like prolongation of the procedure, side effects of drugs that induce hyperemia, additional steps that the operator should perform, the possibility to damage the vessel with the wire, and additional costs. During the last few years, there was a growing interest in the non-invasive assessment of coronary artery lesions, which may provide interventionalist with important physiological information regarding lesion severity and overcome some of the limitations. Several dedicated software solutions are available on the market that could provide an estimation of FFR using 3D reconstruction of the interrogated vessel derived from two separated angiographic projections taken during diagnostic coronary angiography. Furthermore, some of them use data about aortic pressure and frame count to more accurately calculate pressure drop (and FFR). The ideal non-invasive system should be integrated into the workflow of the cath lab and performed online (during the diagnostic procedure), thereby not prolonging procedural time significantly, and giving the operator additional information like vessel size, lesion length, and possible post-PCI FFR value. Following the development of these technologies, they were all evaluated in clinical trials where good correlation and agreement with invasive FFR (considered the gold standard) were demonstrated. Currently, only one trial (FAVOR III China) with clinical outcomes was completed and demonstrated that QFR-guided PCI may provide better results at 1-year follow-up as compared to the angiography-guided approach. We are awaiting the results of a few other trials with clinical outcomes that test the performance of these indices in guiding PCI against either FFR or angiography-based approach, in various clinical settings. Herein we will present an overview of the currently available data, a critical review of the major clinical trials, and further directions of development for the five most widely available non-invasive indices: QFR, vFFR, FFRangio, caFFR, and AccuFFRangio.

Long-term follow-up of patients with chronic total coronary artery occlusion previously randomized to treatment with optimal drug therapy or percutaneous revascularization of chronic total occlusion (COMET-CTO).

Background: The COMET-CTO trial was a randomized prospective study that assessed long-term follow-up in patients with chronic total occlusion (CTO) in coronary arteries treated with percutaneous coronary intervention (PCI) or with optimal medical therapy (OMT). During the 9-month follow-up, the incidence of major adverse cardiac events (MACE) did not differ between the two groups; no death or myocardial infarction (MI) was observed. There was a significant difference in quality of life (QoL), assessed by the Seattle Angina Questionnaire (SAQ), in favor of the PCI group. Here we report long-term follow-up results (56 ± 12 months). Methods: Between October 2015 and May 2017, a total of 100 patients with CTO were randomized into two groups of 50 patients: PCI CTO or OMT group. The primary endpoint of the current study was the incidence of MACE defined as cardiac death, MI, and revascularization [PCI or coronary artery bypass graft (CABG)]. As the secondary exploratory outcome, we analyzed all the cause-mortality rate. Results: Out of 100 randomized patients, 92 were available for long-term follow-up (44 in the PCI group and 48 in the OMT group). The incidence of MACE did not differ significantly between the two groups (p = 0.363). Individual components of MACE were distributed, respectively: cardiac death (OMT vs. PCI group, 6 vs. 3, p = 0.489), MI (OMT vs. PCI group, 1 vs. 0, p = 1), and revascularization (PCI: OMT vs. PCI group, 2 vs. 2, p = 1; CABG: OMT vs. PCI group, 1 vs. 1, p = 1). There was no significant difference between the two groups regarding the individual component of MACE. Six patients died from non-cardiac causes [five deaths were reported in the OMT group and one death in the PCI group (p = 0.206)]. Kaplan-Meier survival curves for MACE did not differ significantly between the study groups (log-rank 0.804, p = 0.370). Regarding the secondary exploratory outcome, a total of 15 patients died at 56 ± 12 months (11 in the OMT and 4 in the PCI group) (p = 0.093). The Kaplan-Meier survival curves for all-cause mortality rates did not differ significantly between the two groups (log rank 3.404, p = 0.065). There were no statistically significant differences between OMT and PCI groups in all five SAQ domains. There was a significant improvement in three SAQ domains in the PCI group: PL (p < 0.001), AF (p = 0.007), and QoL (p = 0.001). Conclusion: After 56 ± 12 months of follow-up, the incidence of MACE, as well as QoL measured by SAQ, did not differ significantly between the PCI and OMT groups.

Prognostic Value of Transthoracic Doppler Echocardiography Coronary Flow Velocity Reserve in Patients With Asymmetric Hypertrophic Cardiomyopathy.

Background Microvascular dysfunction might be a major determinant of clinical deterioration and outcome in patients with hypertrophic cardiomyopathy (HCM). However, long-term prognostic value of transthoracic Doppler echocardiography (TDE) coronary flow velocity reserve (CFVR) on clinical outcome is uncertain in HCM patients. Therefore, the aim of our study was to assess long-term prognostic value of CFVR on clinical outcome in HCM population. Methods and Results We prospectively included 150 HCM patients (82 women; mean age 48±15 years). Patients' clinical characteristics, echocardiographic and CFVR findings (both for left anterior descending [LAD] and posterior descending artery [PD]), were assessed in all patients. The primary outcome was a composite of: HCM related death, heart failure requiring hospitalization, sustained ventricular tachycardia and ischemic stroke. Patients were stratified into 2 subgroups depending on CFVR LAD value: Group 1 (CFVR LAD>2, [n=87]) and Group 2 (CFVR LAD≤2, [n=63]). During a median follow-up of 88 months, 41/150 (27.3%) patients had adverse cardiac events. In Group 1, there were 8/87 (9.2%), whereas in Group 2 there were 33/63 (52.4%, P<0.001 vs. Group 1) adverse cardiac events. By Kaplan-Meier analysis, patients with preserved CFVR LAD had significantly higher cumulative event-free survival rate compared to patients with impaired CFVR LAD (96.4% and 90.9% versus 66.9% and 40.0%, at 5 and 8 years, respectively: log-rank 37.2, P<0.001). Multivariable analysis identified only CFVR LAD≤2 as an independent predictor for adverse cardiac outcome (HR 6.54; 95% CI 2.83-16.30, P<0.001), while CFVR PD was not significantly associated with outcome. Conclusions In patients with HCM, impaired CFVR LAD (≤2) is a strong, independent predictor of adverse cardiac outcome. When the aim of testing is HCM risk stratification and CFVR LAD data are available, the evaluation of CFVR PD is redundant.

The Coronary ARteriogenesis with combined Heparin and EXercise therapy in chronic refractory Angina (CARHEXA) trial: A double-blind, randomized, placebo-controlled stress echocardiographic study.

BACKGROUND: Coronary collateral circulation exerts protective effects on myocardial ischaemia due to coronary artery disease and can be promoted by exercise with heparin co-administration. Whether this arteriogenetic effect is accompanied by functional improvement of left ventricle during stress and lessening of angina symptoms remains unknown. AIMS: To evaluate the anti-ischaemic efficacy of heparin plus exercise in coronary artery disease. METHODS: In a prospective, single-centre, randomized, double-blind study we recruited 32 'no-option' patients (27 males; mean age 61 ± 8 years) with stable angina, exercise-induced ischaemia and coronary artery disease not suitable for revascularization. All underwent a two-week cycle of exercise (two exercise sessions per day, five days per week) and were randomized (n = 16 per group) to intravenous placebo (0.9% saline) versus unfractionated heparin (5.000 IU intravenously), 10 min prior to exercise. We assessed Canadian Cardiovascular Society angina class, stress electrocardiogram and echo parameters (wall motion score index) and computed tomography angiography for collaterals. RESULTS: After two-week cycle, Canadian Cardiovascular Society class statistically decreased in both groups (heparin plus exercise group: 2.6 ± 0.7 to 1.9 ± 0.7, p < 0.001, exercise group: 2.4 ± 0.7 to 2.1 ± 0.9, p = 0.046). Only the heparin plus exercise group improved time-to-ST segment depression (before 270, 228-327 s vs. after 339, 280-360 s, p = 0.012) and wall motion score index (before 1.38 ± 0.25 vs. after 1.28 ± 0.18, p = 0.005). By multi-slice computed tomography angiography, collaterals improved in 12/15 (80%) in the heparin plus exercise group versus 2/16 (12.5%) in the exercise group (p < 0.001). CONCLUSION: A two-week, 10-test cycle of heparin plus exercise is better than exercise in improving angina class, myocardial ischaemia and collaterals by computed tomography angiography.

Functional Assessment of Myocardial Bridging With Conventional and Diastolic Fractional Flow Reserve: Vasodilator Versus Inotropic Provocation.

Background Functional assessment of myocardial bridging (MB) remains clinically challenging because of the dynamic nature of the extravascular coronary compression with a certain degree of intraluminal coronary reduction. The aim of our study was to assess performance and diagnostic value of diastolic-fractional flow reserve (d-FFR) during dobutamine provocation versus conventional-FFR during adenosine provocation with exercise-induced myocardial ischemia as reference. Methods and Results This prospective study includes 60 symptomatic patients (45 men, mean age 57±9 years) with MB on the left anterior descending artery and systolic compression ≥50% diameter stenosis. Patients were evaluated by exercise stress-echocardiography test, and both conventional-FFR and d-FFR in the distal segment of left anterior descending artery during intravenous infusion of adenosine (140 µg/kg per minute) and dobutamine (10-50 µg/kg per minute), separately. Exercise-stress-echocardiography test was positive for myocardial ischemia in 19/60 patients (32%). Conventional-FFR during adenosine and peak dobutamine had similar values (0.84±0.04 versus 0.84±0.06, P=0.852), but d-FFR during peak dobutamine was significantly lower than d-FFR during adenosine (0.76±0.08 versus 0.79±0.08, P=0.018). Diastolic-FFR during peak dobutamine was significantly lower in the exercise-stress-echocardiography test -positive group compared with the exercise- stress-echocardiography test -negative group (0.70±0.07 versus 0.79±0.06, P<0.001), but not during adenosine (0.79±0.07 versus 0.78±0.09, P=0.613). Among physiological indices, d-FFR during peak dobutamine was the only independent predictor of functionally significant MB (odds ratio, 0.870; 95% CI, 0.767-0.986, P=0.03). Receiver-operating characteristics curve analysis identifies the optimal d-FFR during peak dobutamine cut-off ≤0.76 (area under curve, 0.927; 95% CI, 0.833-1.000; P<0.001) with a sensitivity, specificity, and positive and negative predictive value of 95%, 95%, 90%, and 98%, respectively, for identifying MB associated with stress-induced ischemia. Conclusions Diastolic-FFR, but not conventional-FFR, during inotropic stimulation with high-dose dobutamine, in comparison to vasodilatation with adenosine, provides more reliable functional significance of MB in relation to stress-induced myocardial ischemia.

Prognostic Value of Preserved Coronary Flow Velocity Reserve by Noninvasive Transthoracic Doppler Echocardiography in Patients With Angiographically Intermediate Left Main Stenosis.

BACKGROUND: The potential of angiography to evaluate the hemodynamic severity of a left main coronary artery (LM) stenosis is limited. Noninvasive transthoracic Doppler echocardiographic coronary flow velocity reserve (CFVR) evaluation of intermediate coronary stenosis has demonstrated remarkably high negative prognostic value. The aim of this study was to assess clinical outcomes in patients with angiographically intermediate LM stenosis and preserved CFVR (>2.0) as evaluated by transthoracic Doppler echocardiographic CFVR. METHODS: The initial study population included 102 patients with intermediate coronary stenosis of the LM referred for transthoracic Doppler echocardiographic CFVR assessment. Peak diastolic CFVR measurements were performed in the distal segment of the left anterior descending coronary artery after intravenous adenosine (140 µg/kg/min), and CFVR was calculated as the ratio between maximal hyperemic and baseline coronary flow velocity. Nineteen patients had impaired CFVR (≤2.0) and were excluded from further analysis, as well as two patients with poor acoustic windows. The final group consisted of 81 patients (mean age, 60 ± 9 years; 76 men) evaluated for adverse cardiac events including death, myocardial infarction, and revascularization. RESULTS: Mean follow-up duration was 62 ± 26 months. Mean CFVR was 2.4 ± 0.4. Total event-free survival was 75 of 81 (92.6%), as six patients were referred for revascularization (five patients with coronary artery bypass grafting, one patient with percutaneous coronary intervention). There were no documented myocardial infarctions or cardiovascular deaths in the follow-up period. CONCLUSIONS: In patients with angiographically intermediate and equivocal LM stenosis and preserved CFVR values of >2.0, revascularization can be safely deferred.

Prognostic Value of Transthoracic Doppler Echocardiography Coronary Flow Velocity Reserve in Patients with Nonculprit Stenosis of Intermediate Severity Early after Primary Percutaneous Coronary Intervention.

BACKGROUND: Treatment of nonculprit coronary stenosis during primary percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction may be beneficial, but the mode and timing of the intervention are still controversial. The aim of this study was to examine the significance and prognostic value of preserved coronary flow velocity reserve (CFVR) in patients with nonculprit intermediate stenosis early after primary percutaneous coronary intervention. METHODS: Two hundred thirty patients with remaining intermediate (50%-70%) stenosis of non-infarct-related arteries, in whom CFVR was performed within 7 days after primary percutaneous coronary intervention, were prospectively enrolled. Twenty patients with reduced CFVR and positive results on stress echocardiography or impaired fractional flow reserve underwent revascularization and were not included in further analysis. The final study population of 210 patients (mean age, 58 ± 10 years; 162 men) was divided into two groups on the basis of CFVR: group 1, CFVR > 2 (n = 174), and group 2, CFVR ≤ 2 (n = 36). Cardiac death, nonfatal myocardial infarction, and revascularization of the evaluated vessel were considered adverse events. RESULTS: Mean follow-up duration was 47 ± 16 months. Mean CFVR for the whole group was 2.36 ± 0.40. There were six adverse events (3.4%) related to the nonculprit coronary artery in group 1, including one cardiac death, one ST-segment elevation myocardial infarction, and four revascularizations. In group 2, there were 30 adverse events (83.3%, P < .001 vs group 1), including two cardiac deaths, two ST-segment elevation myocardial infarctions, and 26 revascularizations. CONCLUSIONS: In patients with CFVR > 2 of the intermediate nonculprit coronary lesion, deferral of revascularization is safe and associated with excellent long-term clinical outcomes.