Kidney Injury After Minimal Radiographic Contrast Administration in Patients With Acute Coronary Syndromes.

BACKGROUND: Acute kidney injury (AKI) is common in patients with acute coronary syndromes (ACS) treated by percutaneous coronary intervention. OBJECTIVES: Contrast media (CM) volume minimization has been advocated for prevention of AKI. The DyeVert CM diversion system (Osprey Medical, Inc) is designed to reduce CM volume during coronary procedures. METHODS: In this randomized, single-blind, investigator-driven clinical trial conducted in 4 Italian centers from February 4, 2020 to September 13, 2022, 550 participants with ACS were randomly assigned in a 1:1 ratio to the following: 1) the contrast volume reduction (CVR) group (n = 276), in which CM injection was handled by the CM diversion system; and 2) the control group (n = 274), in which a conventional manual or automatic injection syringe was used. The primary endpoint was the rate of AKI, defined as a serum creatinine (sCr) increase ≥0.3 mg/dL within 48 hours after CM exposure. RESULTS: There were 412 of 550 (74.5%) participants with ST-segment elevation myocardial infarction (211 of 276 [76.4%] in the CVR group and 201 of 274 [73.3%] in the control group). The CM volume was lower in the CVR group (95 ± 30 mL vs 160 ± 23 mL; P < 0.001). Seven participants (1 in the CVR group and 6 in the control group) did not have postprocedural sCr values. AKI occurred in 44 of 275 (16%) participants in the CVR group and in 65 of 268 (24.3%) participants in the control group (relative risk: 0.66; 95% CI: 0.47-0.93; P = 0.018). CONCLUSIONS: CM volume reduction obtained using the CM diversion system is effective for prevention of AKI in patients with ACS undergoing invasive procedures. (REnal Insufficiency Following Contrast MEDIA Administration TriaL IV [REMEDIALIV]: NCT04714736).

Neurological Disorders in Takotsubo Syndrome: Clinical Phenotypes and Outcomes.

BACKGROUND: Neurological disorders as a risk factor for Takotsubo syndrome (TTS) are not well characterized. The aim of the study was to evaluate TTS-associated neurological phenotypes and outcome. METHODS AND RESULTS: Patients with TTS enrolled in the international multicenter GEIST (German Italian Spanish Takotsubo) registry were analyzed. Prevalence, clinical characteristics, and short- and long-term outcomes of patients with TTS were recorded. A subgroup analysis of the 5 most represented neurological disorders was performed. In total, 400 (17%) of 2301 patients had neurological disorders. The most represented neurological conditions were previous cerebrovascular events (39%), followed by neurodegenerative disorders (30.7%), migraine (10%), epilepsy (9.5%), and brain tumors (5%). During hospitalization, patients with neurological disorders had longer in-hospital stay (8 [interquartile range, 5-12] versus 6 [interquartile range, 5-9] days; P<0.01) and more often experienced in-hospital complications (27% versus 16%; P=0.01) mainly driven by cardiogenic shock and in-hospital death (12% versus 7.6% and 6.5% versus 2.8%, respectively; both P<0.01). Survival analysis showed a higher mortality rate in neurological patients both at 60 days and long-term (8.8% versus 3.4% and 23.5% versus 10.1%, respectively; both P<0.01). Neurological disorder was an independent predictor of both the 60-day and long-term mortality rate (odds ratio, 1.78 [95% CI, 1.07-2.97]; P=0.02; hazard ratio, 1.72 [95% CI, 1.33-2.22]; both P<0.001). Patients with neurodegenerative disorders had the worst prognosis among the neurological disease subgroups, whereas patients with TTS with migraine had a favorable prognosis (long-term mortality rates, 29.2% and 9.7%, respectively). CONCLUSIONS: Neurological disorders identify a high-risk TTS subgroup for enhanced short- and long-term mortality rate. Careful recognition of neurological disorders and phenotype is therefore needed.

Statin therapy and outcome in Takotsubo syndrome patients: Results from the multicenter international GEIST registry.

BACKGROUND AND AIMS: Several studies have shown that endothelial dysfunction plays a role in the pathogenesis of Takotsubo syndrome (TTS). Given the potential benefit of statin therapy on endothelial dysfunction, we hypothesized that such treatment could improve outcome. Aim of our study was to evaluate clinical characteristics and outcome of TTS patients treated with statin therapy. METHODS: Patients were enrolled in the international multicenter GEIST (GErman Italian Spanish Takotsubo) registry. Demographic data, clinical features and drug therapy at discharge were recorded. Primary study outcome was the occurrence of all-cause death at follow-up. RESULTS: Study population included 2429 consecutive TTS patients: 1293 (53.2%) discharged on statin and 1136 (46.8%) without statin. Patients with statin were older (age 72 ± 11 vs 69 ± 13 years, p < 0.001), with higher prevalence of hypertension (74.3% vs 60.3%, p < 0.001), diabetes (21.1% vs 14.7%, p < 0.001), dyslipidemia (56.1% vs 23.3%, p < 0.001), history of coronary artery disease (13.3% vs 6.3%, p < 0.001) and lower rates of in-hospital complications (14.7% vs 19.3%, p = 0.003). Survival analysis showed similar mortality rates between groups (log rank p = 0.803). At univariable analysis, statin therapy at discharge was not associated with lower mortality (HR: 0.97, 95% CI 0.74-1.26, p = 0.803). At multivariable analysis age (HR: 1.06 95% CI 1.04-1.08, p < 0.001), male sex (HR: 1.83, 95% CI 1.20-2.80, p = 0.005), diabetes (HR: 2.55, 95% CI 1.83-3.54 p < 0.001), malignancies (HR: 2.41, 95% CI 1.68-3.44, p < 0.001) and physical trigger (HR: 2.24, 95% CI 1.62-3.10, p < 0.001) were associated with increased mortality. CONCLUSIONS: Statin therapy after a TTS event was not associated with better prognosis at follow-up.

Smoking influence in Takotsubo syndrome: insights from an international cohort.

Aims: To assess the influence of tobacco on acute and long-term outcomes in Takotsubo syndrome (TTS). Methods: Patients with TTS from the international multicenter German Italian Spanish Takotsubo registry (GEIST) were analyzed. Comparisons between groups were performed within the overall cohort, and an adjusted analysis with 1:1 propensity score matching was conducted. Results: Out of 3,152 patients with TTS, 534 (17%) were current smokers. Smoker TTS patients were younger (63 ± 11 vs. 72 ± 11 years, p < 0.001), less frequently women (78% vs. 90%, p < 0.001), and had a lower prevalence of hypertension (59% vs. 69%, p < 0.01) and diabetes mellitus (16% vs. 20%, p = 0.04), but had a higher prevalence of pulmonary (21% vs. 15%, p < 0.01) and/or psychiatric diseases (17% vs. 12%, p < 0.01). On multivariable analysis, age less than 65 years [OR 3.85, 95% CI (2.86-5)], male gender [OR 2.52, 95% CI (1.75-3.64)], history of pulmonary disease [OR 2.56, 95% CI (1.81-3.61)], coronary artery disease [OR 2.35, 95% CI (1.60-3.46)], and non-apical ballooning form [OR 1.47, 95% CI (1.02-2.13)] were associated with smoking status. Propensity score matching (PSM) 1:1 yielded 329 patients from each group. Smokers had a similar rate of in-hospital complications but longer in-hospital stays (10 vs. 9 days, p = 0.01). During long-term follow-up, there were no differences in mortality rates between smokers and non-smokers (5.6% vs. 6.9% yearly in the overall, p = 0.02, and 6.6%, vs. 7.2% yearly in the matched cohort, p = 0.97). Conclusions: Our findings suggest that smoking may influence the clinical presentation and course of TTS with longer in-hospital stays, but does not independently impact mortality.

Trigger-Associated Clinical Implications and Outcomes in Takotsubo Syndrome: Results From the Multicenter GEIST Registry.

Background Takotsubo syndrome is usually triggered by a stressful event. The type of trigger seems to influence the outcome and should therefore be considered separately. Methods and Results Patients included in the GEIST (German-Italian-Spanish Takotsubo) registry were categorized according to physical trigger (PT), emotional trigger (ET), and no trigger (NT) of Takotsubo syndrome. Clinical characteristics as well as outcome predictors were analyzed. Overall, 2482 patients were included. ET was detected in 910 patients (36.7%), PT in 885 patients (34.4%), and NT was observed in 717 patients (28.9%). Compared with patients with PT or NT, patients with ET were younger, less frequently men, and had a lower prevalence of comorbidities. Adverse in-hospital events (NT: 18.8% versus PT: 27.1% versus ET: 12.1%, P<0.001) and long-term mortality rates (NT: 14.4% versus PT: 21.6% versus ET: 8.5%, P<0.001) were significantly lower in patients with ET. Increasing age (P<0.001), male sex (P=0.007), diabetes (P<0.001), malignancy (P=0.002), and a neurological disorder (P<0.001) were associated with a higher risk of long-term mortality, while chest pain (P=0.035) and treatment with angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (P=0.027) were confirmed as independent predictors for a lower risk of long-term mortality. Conclusions Patients with ET have better clinical conditions and a lower mortality rate. Increasing age, male sex, malignancy, a neurological disorder, chest pain, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, and diabetes were confirmed as predictors of long-term mortality.

Gender Differences in Takotsubo Syndrome.

BACKGROUND: Male sex in takotsubo syndrome (TTS) has a low incidence and it is still not well characterized. OBJECTIVES: The aim of the present study is to describe TTS sex differences. METHODS: TTS patients enrolled in the international multicenter GEIST (GErman Italian Spanish Takotsubo) registry were analyzed. Comparisons between sexes were performed within the overall cohort and using an adjusted analysis with 1:1 propensity score matching for age, comorbidities, and kind of trigger. RESULTS: In total, 286 (11%) of 2,492 TTS patients were men. Male patients were younger (age 69 ± 13 years vs 71 ± 11 years; P = 0.005), with higher prevalence of comorbid conditions (diabetes mellitus 25% vs 19%; P = 0.01; pulmonary diseases 21% vs 15%; P = 0.006; malignancies 25% vs 13%; P < 0.001) and physical trigger (55 vs 32% P < 0.01). Propensity-score matching yielded 207 patients from each group. After 1:1 propensity matching, male patients had higher rates of cardiogenic shock and in-hospital mortality (16% vs 6% and 8% vs 3%, respectively; both P < 0.05). Long-term mortality rate was 4.3% per patient-year (men 10%, women 3.8%). Survival analysis showed higher mortality rate in men during the acute phase in both cohorts (overall: P < 0.001; matched: P = 0.001); mortality rate after 60 days was higher in men in the overall (P = 0.002) but not in the matched cohort (P = 0.541). Within the overall population, male sex remained independently associated with both in-hospital (OR: 2.26; 95% CI: 1.16-4.40) and long-term mortality (HR: 1.83; 95% CI: 1.32-2.52). CONCLUSIONS: Male TTS is featured by a distinct high-risk phenotype requiring close in-hospital monitoring and long-term follow-up.

Incidence and Clinical Impact of Right Ventricular Involvement (Biventricular Ballooning) in Takotsubo Syndrome: Results From the GEIST Registry.

BACKGROUND: The short- and long-term prognosis of Takotsubo syndrome (TTS) presenting with right ventricular (RV) involvement remains poorly understood. RESEARCH QUESTION: What is the incidence and clinical outcome of RV involvement in TTS? STUDY DESIGN AND METHODS: This study analyzed 839 consecutive patients with TTS (758 female subjects and 81 male subjects) in a multicenter registry. RV involvement was defined as wall motion abnormality of the RV free wall, with or without apical involvement. The median long-term follow-up was 2.1 years (interquartile range, 0.3-4.5 years). The primary outcome was in-hospital and out-of-hospital all-cause mortality. The secondary end point was a composite of in-hospital death, thromboembolic events, cardiogenic shock, pulmonary edema, and malignant arrhythmias. RESULTS: The incidence of RV involvement in TTS was 11% (n = 93). More often patients with RV involvement were male compared with patients without RV involvement (P = .02). There was a slight difference in the left ventricular ejection fraction measured in patients with RV involvement vs those patients with isolated left ventricular TTS (38 ± 10% vs 40 ± 10%; P = .03). No major differences in terms of comorbidities were observed between groups except regarding a history of cancer, which was significantly more prevalent in patients with TTS presenting with RV involvement (P = .03). Physical stressors were more prevalent in the RV group (P < .01), whereas emotional stressors were less prevalent (P < .01). Patients with RV involvement had a higher incidence of in-hospital cardiogenic shock (P = .02). The primary outcome (in- and out-of-hospital all-cause mortality) was observed in 12.8% of patients without RV involvement compared with 29% of patients with RV involvement. Although the in-hospital mortality rate was similar in both groups, a higher out-of-hospital all-cause mortality rate (log-rank test, P = .008) was observed in the RV involvement group. The Cox multivariable regression analysis showed that physical triggers were independent predictors of RV involvement. INTERPRETATION: RV involvement defines a high-risk cohort of patients with TTS. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov; No.: NCT04361994; URL: www.clinicaltrials.gov.

Challenges and Open Issues in Transcatheter Mitral Valve Implantation: Smooth Seas Do Not Make Skillful Sailors.

According to the European and American guidelines, surgery represents the treatment of choice for mitral valve (MV) disease. However, a number of patients are deemed unsuitable for surgery due to a prohibitive/high operative risk. In such cases, transcatheter therapies aiming at MV repair have been proven to be a valuable alternative and have been recently introduced in the latest American guidelines on valvular heart disease. Indeed, percutaneous repair techniques, particularly transcatheter edge-to-edge, have gained a broad experience and demonstrated to be safe and effective. However, given the complexity and heterogeneity of MV anatomy and pathology, transcatheter MV implantation (TMVI) has grown as a possible alternative to percutaneous MV repair. Current data about TMVI are still limited and come from different settings: valve-in-native MV, valve-in-valve (ViV), valve-in-ring (ViR), and valve-in-mitral annular calcification. Preliminary data are promising although several open issues still need to be addressed. This paper provides a comprehensive review of the available devices in the different clinical settings, to discuss potentialities, limitations, and future directions for TMVI.

Prevalence, management, and outcome of adverse rhythm disorders in takotsubo syndrome: insights from the international multicenter GEIST registry.

One important complication related to takotsubo syndrome (TTS) is adverse rhythm disorders. Our study was conducted to determine the incidence and management of adverse rhythm disorders in TTS and its long-term prognostic impact. We analyzed 906 TTS patients from 9 European centers. Patients were divided into the adverse rhythm disorders group (encompassing ventricular tachycardia, ventricular fibrillation, torsade de pointes, and asystole or complete atrioventricular block) and non-adverse rhythm disorders group. In our study cohort, we identified 67 (7.4%) patients with presence of adverse rhythm disorders. TTS patients were followed up over a period of 2.8 years. In the adverse rhythm disorders group, 18% of patients presented adverse rhythm disorders before hospital admission. Asystole and/or AV block were significantly more presented before admission (13 patients versus 8 patients; p < 0.01), whereas ventricular tachyarrhythmias were more presented in-hospital (4 patients versus 42 patients; p < 0.01). Adverse rhythm disorders patients suffered more frequently from cardiogenic shock (31% versus 7.6%, p < 0.01) and in-hospital death (10.9% versus 3.6%; p < 0.01). Furthermore, the long-term survival was significantly impaired in adverse rhythm disorders patients as compared with non-adverse rhythm disorders patients; (log-rank p < 0.01). Using multivariate Cox regression analysis, cardiogenic shock (HR 2.86, 95% CI 1.1-6.9; p = 0.02) was identified as independent predictors of adverse rhythm disorders. The short- and long-term mortality rate of TTS patients presenting with adverse rhythm disorders was significantly higher than in TTS patients presenting without it. Therefore, TTS patients with adverse rhythm disorders should be carefully monitored during hospital stay and at long-term follow-up.

Large coronary aneurysm following laser angioplasty of the left anterior descending coronary artery.

Coronary aneurysm is a rare complication after coronary excimer laser angioplasty. A 45-year-old woman underwent laser angioplasty and bare metal direct stenting of the proximal segment of the left anterior descending artery (LAD); after 3 months, angiographic follow-up showed significant ostial stenosis of the LAD with a large sacciform aneurysm and diffuse intrastent restenosis.

Prediction of long-term ischemic events by noninvasively assessed coronary flow reserve.

BACKGROUND: Coronary flow reserve (CFR) by adenosine echocardiography in left anterior descending (LAD) or posterior descending coronary arteries may predict clinical outcome. METHODS: We used models accounting (Cox's model) or not (logistic regression and neural network) for time to event and either considered (forced models) or not (stepwise logistic regression and neural network models) all among 21 covariates to predict 1-year composite events after LAD CFR. RESULTS: There were 553 consecutive patients with coronary artery disease (CAD): 89 patients had also posterior descending CFR. During 1-year follow-up 328 patients were event-free, 35 had composite ischemic events and 190 underwent short-term revascularization. LAD and posterior descending CFR (respectively, 1.53 ±â€Š0.83, N = 225 and 1.84 ±â€Š0.80, N = 42) were significantly (P < 0.0001) lower in patients with events (or with revascularization following CFR measurement) than in those without (respectively, 3.13 ±â€Š0.84, N = 328, and 2.53 ±â€Š0.72, N = 47). Using LAD CFR as a continuous covariate, by both forced Cox's and logistic regression, coefficients (t values, respectively, -14.11 and -10.19) were significant (both P < 0.00001) to predict outcome. Global predictive accuracies by neural network, adopting a receiver operating characteristic areas under the curve (ROC) assessment, were excellent (>0.91) and the role of LAD CFR among predictors was overwhelming. Other indices of myocardial ischemia and the presence of coronary stenoses or previous infarction did not modify the multivariable predictive role of LAD CFR. When patients with revascularization were discounted, the LAD CFR predictive role was the same. CONCLUSIONS: Thus, adenosine echocardiography-based LAD CFR predicts 1-year composite ischemic events in patients with CAD, independent of the multivariable model adopted. Posterior descending CFR also has a role.

Single coronary artery with anomalous origin of right coronary artery from left main stem.

We report the case of a 57-year-old man with unstable angina that was taken up for coronary angiography, which showed an anomalous right coronary artery originating from left main stem.

Clinical value of echocardiographic assessment of coronary flow reserve after left anterior descending coronary artery stenting in an unselected population.

BACKGROUND: Transthoracic Doppler echocardiography is a valuable tool to measure coronary flow reserve (CFR) and detect in-stent restenosis (ISR) after percutaneous coronary angioplasty in selected series of patients. OBJECTIVES: To assess the usefulness of coronary flow reserve measured by echocardiography in detecting significant (> or =70%) ISR of the left anterior descending coronary artery in a large unselected population. METHODS: Two hundred and twenty-three patients (age 61 +/- 10 years; 168 men) treated with left anterior descending stenting underwent CFR measurement by transthoracic Doppler echocardiography and venous adenosine infusion 24-72 h before control coronary angiography. Coronary-active drugs were continued, and patients with multiple risk factors and old anterior-apical myocardial infarction were included. RESULTS: Significant ISR occurred in 56 patients (25%). Patients with ISR had higher basal coronary flow velocity (27 +/- 10 cm/s vs. 24 +/- 7 cm/s; P < 0.002) and lower CFR (1.5 +/- 0.5 vs. 2.7 +/- 0.6; P < 0.0001) than those without ISR. A linear relation was found between ISR and CFR (r = -0.73; P < 0.0001) and remained significant after adjustment for blood pressure and heart rate (r = -0.74; P < 0.0001). A CFR less than two identified significant ISR (sensitivity 88%, specificity 88%, area under the curve = 0.943; P < 0.001). In a multivariate model of CFR prediction, myocardial infarction and heart rate were slightly contributory (ss = -0.19, P < 0.01; ss = -0.16, P < 0.03, respectively), whereas ISR had a large influence (ss = -0.66; P < 0.0001). The inverse correlation between ISR and CFR persisted in patients with myocardial infarction (r = -0.64; P < 0.0001) and in those treated with beta-blockers (r = -0. 71; P < 0.0001). CONCLUSION: Echocardiographic measurement of CFR detects significant left anterior descending ISR in unselected patients with multiple risk factors, old anterior-apical myocardial infarction, and taking beta-blockers.

Evaluation of flow in the left anterior descending coronary artery but not in the left internal mammary artery graft predicts significant stenosis of the arterial conduit.

OBJECTIVES: The purpose of this study was to evaluate which Doppler-derived flow index best predicts new distal left anterior descending coronary artery (LAD) stenosis in patients with left internal mammary artery (LIMA) graft. BACKGROUND: The LIMA flow measurement has been proposed to assess graft function, but it may be misleading in case of new distal LAD stenosis and/or competitive flow from native LAD. Distal LAD coronary flow reserve (CFR: hyperemic/baseline peak flow velocity ratio) may be more appropriate. METHODS: The LIMA and distal LAD flow was measured by transthoracic Doppler echocardiography in 96 patients undergoing diagnostic/therapeutic coronary angiography, 7 +/- 4 years after cardiac bypass surgery. The LIMA flow indexes (systolic-to-diastolic peak velocity ratio [SDPVr] >1, diastolic time velocity integral fraction [DTVIf] <0.5, and CFR <2) and LAD CFR <2 were used to predict > or =70% new LAD stenosis. RESULTS: The LAD CFR <2 predicted new LAD stenosis, found in 21 of 77 patients without competitive flow from native LAD, with significantly higher diagnostic accuracy (98%) than LIMA flow indexes (SDPVr >1 = 61%, DTVIf <0.5 = 69%, and CFR <2 = 72%). The LIMA flow indexes were abnormal in 17 of 19 patients with competitive graft flow, but only 5 had graft restriction, and none had significant LAD stenosis. In a multivariate model of new distal LAD stenosis prediction, competitive flow from native LAD reduced the predictive role of LIMA but not of LAD CFR. CONCLUSIONS: In patients without competitive flow from native LAD, LAD CFR is more accurate for the detection of LAD stenosis than LIMA CFR. In patients with competitive graft flow, abnormal LIMA flow patterns and blunted LIMA CFR do not reflect downstream LAD flow as LAD CFR does.

Coronary flow reserve of the angiographically normal left anterior descending coronary artery in patients with remote coronary artery disease.

Coronary artery disease (CAD) has been suggested to alter coronary flow reserve (CFR; the ratio between hyperemic and baseline coronary flow velocities) not only in territories supplied by stenotic arteries but also in angiographically normal, remote regions. However, few data exist regarding the left anterior descending (LAD) coronary artery as the normal index artery. The influence of remote CAD on CFR of the angiographically normal LAD was evaluated with transthoracic Doppler ultrasound to measure CFR in the LAD during 90 seconds of venous adenosine infusion (140 microg/kg/min) in 122 subjects who were assigned to 1 group; group 1 comprised 49 controls without angiographically detectable CAD, and group 2 consisted of 73 patients with an angiographically normal LAD and remote CAD. Group 2 was divided into 4 subgroups: 16 patients with previous remote percutaneous coronary intervention (group 2A); 13 patients with significant remote stenosis (group 2B); 23 patients with previous remote myocardial infarction and percutaneous coronary intervention (group 2C); and 21 patients with previous remote myocardial infarction but no percutaneous coronary intervention (group 2D). CFR in the LAD was not significantly different in groups 1 and 2 (3.08 +/- 0.61 and 3.03 +/- 0.69, respectively, p = NS). Decreased ejection fraction and increased wall motion score index in patients with remote CAD (p < 0.00001) and multivessel CAD did not affect CFR in the LAD (group 2A 3.18 +/- 0.77; group 2B 3.05 +/- 0.65; group 2C 3.07 +/- 0.79; group 2D 2.86 +/- 0.50, respectively; F = 0.63, p = NS). In conclusion, CFR of an angiographically normal LAD is preserved in patients with remote CAD, even in the presence of previous remote myocardial infarction and wall motion abnormalities.

Usefulness of coronary flow reserve measured by transthoracic coronary Doppler ultrasound to detect severe left anterior descending coronary artery stenosis.

Transthoracic coronary Doppler ultrasound during venous adenosine infusion showed damped (<1) coronary flow velocity reserve in patients with severe left anterior descending coronary artery stenosis. Damped coronary flow reserve discriminated severe from nonsevere stenosis with high sensitivity, specificity, and positive predictive accuracy, and is a unique noninvasive tool to identify high-risk patients.

Noninvasive coronary flow reserve assessed by transthoracic coronary Doppler ultrasound in patients with left anterior descending coronary artery stents.

Noninvasive measurement of coronary flow reserve (CFR) (hyperemic/flow velocity ratio at rest) by transthoracic Doppler echocardiography showed normalization of flow in the left anterior descending (LAD) coronary artery early after stenting. We hypothesized that noninvasive CFR may reveal in-stent restenosis at follow-up. Therefore, we studied 134 patients, 0 to 72 months after successful proximal-middle LAD stenting, and 38 controls. LAD flow velocity was measured by transthoracic Doppler echocardiography during 90 seconds venous adenosine infusion (140 microg/kg/min). CFR was measured in diastole. According to angiography, patients who received stents were divided into 3 groups: group I, <50% LAD in-stent restenosis (n = 83); group II, nonsignificant (50% to 69%) LAD in-stent restenosis (n = 17); and group III, significant (> or = 70%) LAD in-stent restenosis (n = 34). LAD CFR was similar in group I and controls (2.90 +/- 0.58 vs 3.05 +/- 0.81; p = NS), it was slightly lower in group II (2.42 +/- 0.33) compared with controls and group I (p <0.001 vs both), and clearly abnormal (<2) in group III (1.38 +/- 0.48) compared with controls, and groups I and II (p <0.001). A CFR <2 had 91% sensitivity, 95% specificity, and 96% positive and 97% negative predictive values to detect significant stenosis in patients with LAD stents. Our data show that noninvasive Doppler assessment of CFR allows identification of significant LAD in-stent restenosis, based on a cut-off value of <2.

Measurement of coronary flow reserve in the anterior and posterior descending coronary arteries by transthoracic Doppler ultrasound.

We describe for the first time transthoracic Doppler ultrasound assessment of coronary flow reserve (CFR) in both the posterior descending (PDA) and left anterior descending (LAD) coronary arteries. CFR (hyperemic/resting diastolic flow velocity ratio) was measured by 90-second intravenous adenosine infusion (140 microg/kg/min). Baseline PDA flow was detected in 62 of 81 subjects (76%), and the CFR was measurable in 44 of them (54%) because of adenosine-induced hyperventilation. According to angiography, these 44 subjects were divided into 3 groups: group 1 (0% to 29% stenosis), group 2 (30% to 69% stenosis), and group 3 (> or =70% stenosis). PDA CFR was 2.62 +/- 0.25 in 17 patients in group 1, 2.33 +/- 0.32 in 9 patients in group 2, and 1.40 +/- 0.54 in 18 patients in group 3 (F = 41.83, p <0.0001). LAD CFR was 3.31 +/- 0.54 in 15 patients in group 1, 2.49 +/- 0.71 in 10 patients in group 2, and 1.12 +/- 0.49 in 19 patients in group 3 (F = 65.68, p <0.0001). A cut-off of <2 identified > or =70% stenosis in both of the arteries supplying the PDA and in the LAD. Noninvasive measurement of PDA CFR is feasible and may improve with technologic advancement and the use of selective adenosine receptor agonists, thus preventing hyperventilation.