Thomas T. Tsai

Long-term survival in patients presenting with type B acute aortic dissection: Insights from the international registry of acute aortic dissection

Background— Follow-up survival studies in patients with acute type B aortic dissection have been restricted to a small number of patients in single centers. We used data from a contemporary registry of acute type B aortic dissection to better understand factors associated with adverse long-term survival. Methods and Results— We examined 242 consecutive patients discharged alive with acute type B aortic dissection enrolled in the International Registry of Acute Aortic Dissection (IRAD) between 1996 and 2003. Kaplan-Meier survival curves were constructed, and Cox proportional hazards analysis was performed to identify independent predictors of follow-up mortality. Three-year survival for patients treated medically, surgically, or with endovascular therapy was 77.6±6.6%, 82.8±18.9%, and 76.2±25.2%, respectively (median follow-up 2.3 years, log-rank P=0.61). Independent predictors of follow-up mortality included female gender (hazard ratio [HR], 1.99; 95% confidence interval [CI], 1.07 to 3.71; P=0.03), a history of prior aortic aneurysm (HR, 2.17; 95% CI, 1.03 to 4.59; P=0.04), a history of atherosclerosis (HR, 2.48; 95% CI, 1.32 to 4.66; P<0.01), in-hospital renal failure (HR, 2.55; 95% CI, 1.15 to 5.63; P=0.02), pleural effusion on chest radiograph (HR, 2.56; 95% CI, 1.18 to 5.58; P=0.02), and in-hospital hypotension/shock (HR, 12.5; 95% CI, 3.24 to 48.21; P<0.01). Conclusions— Contemporary follow-up mortality in patients who survive to hospital discharge with acute type B aortic dissection is high, approaching 1 in every 4 patients at 3 years. Current treatment and follow-up surveillance require further study to better understand and optimize care for patients with this complex disease.

Aortic Diameter ≥5.5 cm Is Not a Good Predictor of Type A Aortic Dissection Observations From the International Registry of Acute Aortic Dissection (IRAD)

Background— Studies of aortic aneurysm patients have shown that the risk of rupture increases with aortic size. However, few studies of acute aortic dissection patients and aortic size exist. We used data from our registry of acute aortic dissection patients to better understand the relationship between aortic diameter and type A dissection. Methods and Results— We examined 591 type A dissection patients enrolled in the International Registry of Acute Aortic Dissection between 1996 and 2005 (mean age, 60.8 years). Maximum aortic diameters averaged 5.3 cm; 349 (59%) patients had aortic diameters <5.5 cm and 229 (40%) patients had aortic diameters <5.0 cm. Independent predictors of dissection at smaller diameters (<5.5 cm) included a history of hypertension (odds ratio, 2.17; 95% confidence interval, 1.03 to 4.57; P=0.04), radiating pain (odds ratio, 2.08; 95% confidence interval, 1.08 to 4.0; P=0.03), and increasing age (odds ratio, 1.03; 95% confidence interval, 1.00 to 1.05; P=0.03). Marfan syndrome patients were more likely to dissect at larger diameters (odds ratio, 14.3; 95% confidence interval, 2.7 to 100; P=0.002). Mortality (27% of patients) was not related to aortic size. Conclusions— The majority of patients with acute type A acute aortic dissection present with aortic diameters <5.5 cm and thus do not fall within current guidelines for elective aneurysm surgery. Methods other than size measurement of the ascending aorta are needed to identify patients at risk for dissection.

Acute aortic syndromes

In 1760, Dr Nicholls, physician to King George II, first described on necropsy an acute aortic dissection. Over the course of more than 200 years, we have developed a growing awareness and understanding of acute and chronic aortic syndromes. Recent advances in imaging and therapeutic techniques have further emphasized the importance of early diagnosis of acute aortic syndromes, which continues to be crucial to survival. However, we continue to be uncomfortable in the diagnosis and management of this highly lethal disorder. In the present report, we review the etiology, pathophysiology, clinical presentation, outcomes, and therapeutic approaches to acute aortic syndromes. In each section, we summarize the most clinically relevant issues as “take home points” (THPs) to affirm their importance in the diagnosis and management of this disorder. Acute aortic syndrome is the modern term that includes aortic dissection, intramural hematoma (IMH), and symptomatic aortic ulcer. In the classic sense, acute aortic dissection requires a tear in the aortic intima that commonly is preceded by medial wall degeneration or cystic media necrosis.1 Blood passes through the tear separating the intima from the media or adventitia, creating a false lumen. Propagation of the dissection can proceed in anterograde or retrograde fashion from the initial tear involving side branches and causing complications such as malperfusion syndromes, tamponade, or aortic valve insufficiency.2–5 Both acquired and genetic conditions share a common pathway leading to the breakdown in the integrity of the intima. All mechanisms that weaken the media layers of the aorta will eventually lead to higher wall stress, which can induce aortic dilatation and aneurysm formation, eventually resulting in intramural hemorrhage, aortic dissection, or rupture. The factors culminating in a clinical dissection are quite diverse. The most common risk condition for aortic dissection is hypertension, with chronic exposure of the aorta to …

Complicated Acute Type B Dissection: Is Surgery Still the Best Option?: A Report From the International Registry of Acute Aortic Dissection

OBJECTIVES Impact on survival of different treatment strategies was analyzed in 571 patients with acute type B aortic dissection enrolled from 1996 to 2005 in the International Registry of Acute Aortic Dissection. BACKGROUND The optimal treatment for acute type B dissection is still a matter of debate. METHODS Information on 290 clinical variables were compared, including demographics; medical history; clinical presentation; physical findings; imaging studies; details of medical, surgical, and endovascular management; in-hospital clinical events; and in-hospital mortality. RESULTS Of the 571 patients with acute type B aortic dissection, 390 (68.3%) were treated medically, 59 (10.3%) with standard open surgery and 66 (11.6%) with an endovascular approach. Patients who underwent emergency endovascular or open surgery were younger (mean age 58.8 years, p < 0.001) than their counterparts treated conservatively, and had male preponderance and hypertension in 76.9%. Patients submitted to surgery presented with a wider aortic diameter than patients treated by interventional techniques or by medical therapy (5.36 +/- 1.7 cm vs. 4.62 +/- 1.4 cm vs. 4.47 +/- 1.4 cm, p = 0.003). In-hospital complications occurred in 20% of patients subjected to endovascular technique and in 40% of patients after open surgical repair. In-hospital mortality was significantly higher after open surgery (33.9%) than after endovascular treatment (10.6%, p = 0.002). After propensity and multivariable adjustment, open surgical repair was associated with an independent increased risk of in-hospital mortality (odds ratio: 3.41, 95% confidence interval: 1.00 to 11.67, p = 0.05). CONCLUSIONS In the International Registry of Acute Aortic Dissection, the less invasive nature of endovascular treatment seems to provide better in-hospital survival in patients with acute type B dissection; larger randomized trials or comprehensive registries are needed to access impact on outcomes.

Acute Aortic Dissection: Perspectives from the International Registry of Acute Aortic Dissection (IRAD)

Acute aortic dissection is a rare but deadly disease first described over 200 years ago by the physician to the late King George II on necropsy. Over the ensuing 2 centuries, the understanding of the pathophysiology, presentation, diagnosis, treatment and follow-up has matured. In an effort to understand the contemporary treatment of this disease, the International Registry of Acute Aortic Dissection (IRAD) has enrolled over 2000 patients over the past 12 years. In this article we summarize the key lessons learned from this multi-national registry of patients presenting with acute aortic dissection.

Nonobstructive coronary artery disease and risk of myocardial infarction.

IMPORTANCE Little is known about cardiac adverse events among patients with nonobstructive coronary artery disease (CAD). OBJECTIVE To compare myocardial infarction (MI) and mortality rates between patients with nonobstructive CAD, obstructive CAD, and no apparent CAD in a national cohort. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study of all US veterans undergoing elective coronary angiography for CAD between October 2007 and September 2012 in the Veterans Affairs health care system. Patients with prior CAD events were excluded. EXPOSURES Angiographic CAD extent, defined by degree (no apparent CAD: no stenosis >20%; nonobstructive CAD: ≥1 stenosis ≥20% but no stenosis ≥70%; obstructive CAD: any stenosis ≥70% or left main [LM] stenosis ≥50%) and distribution (1, 2, or 3 vessel). MAIN OUTCOMES AND MEASURES The primary outcome was 1-year hospitalization for nonfatal MI after the index angiography. Secondary outcomes included 1-year all-cause mortality and combined 1-year MI and mortality. RESULTS Among 37,674 patients, 8384 patients (22.3%) had nonobstructive CAD and 20,899 patients (55.4%) had obstructive CAD. Within 1 year, 845 patients died and 385 were rehospitalized for MI. Among patients with no apparent CAD, the 1-year MI rate was 0.11% (n = 8, 95% CI, 0.10%-0.20%) and increased progressively by 1-vessel nonobstructive CAD, 0.24% (n = 10, 95% CI, 0.10%-0.40%); 2-vessel nonobstructive CAD, 0.56% (n = 13, 95% CI, 0.30%-1.00%); 3-vessel nonobstructive CAD, 0.59% (n = 6, 95% CI, 0.30%-1.30%); 1-vessel obstructive CAD, 1.18% (n = 101, 95% CI, 1.00%-1.40%); 2-vessel obstructive CAD, 2.18% (n = 110, 95% CI, 1.80%-2.60%); and 3-vessel or LM obstructive CAD, 2.47% (n = 137, 95% CI, 2.10%-2.90%). After adjustment, 1-year MI rates increased with increasing CAD extent. Relative to patients with no apparent CAD, patients with 1-vessel nonobstructive CAD had a hazard ratio (HR) for 1-year MI of 2.0 (95% CI, 0.8-5.1); 2-vessel nonobstructive HR, 4.6 (95% CI, 2.0-10.5); 3-vessel nonobstructive HR, 4.5 (95% CI, 1.6-12.5); 1-vessel obstructive HR, 9.0 (95% CI, 4.2-19.0); 2-vessel obstructive HR, 16.5 (95% CI, 8.1-33.7); and 3-vessel or LM obstructive HR, 19.5 (95% CI, 9.9-38.2). One-year mortality rates were associated with increasing CAD extent, ranging from 1.38% among patients without apparent CAD to 4.30% with 3-vessel or LM obstructive CAD. After risk adjustment, there was no significant association between 1- or 2-vessel nonobstructive CAD and mortality, but there were significant associations with mortality for 3-vessel nonobstructive CAD (HR, 1.6; 95% CI, 1.1-2.5), 1-vessel obstructive CAD (HR, 1.9; 95% CI, 1.4-2.6), 2-vessel obstructive CAD (HR, 2.8; 95% CI, 2.1-3.7), and 3-vessel or LM obstructive CAD (HR, 3.4; 95% CI, 2.6-4.4). Similar associations were noted with the combined outcome. CONCLUSIONS AND RELEVANCE In this cohort of patients undergoing elective coronary angiography, nonobstructive CAD, compared with no apparent CAD, was associated with a significantly greater 1-year risk of MI and all-cause mortality. These findings suggest clinical importance of nonobstructive CAD and warrant further investigation of interventions to improve outcomes among these patients.

Contemporary Incidence, Predictors, and Outcomes of Acute Kidney Injury in Patients Undergoing Percutaneous Coronary Interventions: Insights From the NCDR Cath-PCI Registry

OBJECTIVES This study sought to examine the contemporary incidence, predictors and outcomes of acute kidney injury in patients undergoing percutaneous coronary interventions. BACKGROUND Acute kidney injury (AKI) is a serious and potentially preventable complication of percutaneous coronary interventions (PCIs) that is associated with adverse outcomes. The contemporary incidence, predictors, and outcomes of AKI are not well defined, and clarifying these can help identify high-risk patients for proactive prevention. METHODS A total of 985,737 consecutive patients underwent PCIs at 1,253 sites participating in the National Cardiovascular Data Registry Cath-PCI registry from June 2009 through June 2011. AKI was defined on the basis of changes in serum creatinine level in the hospital according to the Acute Kidney Injury Network (AKIN) criteria. Using multivariable regression analyses with generalized estimating equations, we identified patient characteristics associated with AKI. RESULTS Overall, 69,658 (7.1%) patients experienced AKI, with 3,005 (0.3%) requiring new dialysis. On multivariable analyses, the factors most strongly associated with development of AKI included ST-segment elevation myocardial infarction (STEMI) presentation (odds ratio [OR]: 2.60; 95% confidence interval [CI]: 2.53 to 2.67), severe chronic kidney disease (OR: 3.59; 95% CI: 3.47 to 3.71), and cardiogenic shock (OR: 2.92; 95% CI: 2.80 to 3.04). The in-hospital mortality rate was 9.7% for patients with AKI and 34% for those requiring dialysis compared with 0.5% for patients without AKI (p < 0.001). After multivariable adjustment, AKI (OR: 7.8; 95% CI: 7.4 to 8.1, p < 0.001) and dialysis (OR: 21.7; 95% CI: 19.6 to 24.1; p < 0.001) remained independent predictors of in-hospital mortality. CONCLUSIONS Approximately 7% of patients undergoing a PCI experience AKI, which is strongly associated with in-hospital mortality. Defining strategies to minimize the risk of AKI in patients undergoing PCI are needed to improve the safety and outcomes of the procedure.

Tear size and location impacts false lumen pressure in an ex vivo model of chronic type B aortic dissection.

BACKGROUND Follow-up mortality is high in patients with type B aortic dissection (TB-AD) approaching one in four patients at 3 years. A predictor of increased mortality is partial thrombosis of the false lumen which may occlude distal tears. The hemodynamic consequences of differing tear size, location, and patency within the false lumen is largely unknown. We examined the impact of intimal tear size, tear number, and location on false lumen pressure. METHODS In an ex-vivo model of chronic type B aortic dissection connected to a pulsatile pump, simultaneous pressures were measured within the true and false lumen. Experiments were performed in different dissection models with tear sizes of 6.4 mm and 3.2 mm in the following configurations; model A: proximal and distal tear simulating the most common hemodynamic state in patients with TB-AD; model B: proximal tear only simulating patients with partial thrombosis and occlusion of distal tear; and model C: distal tear only simulating patients sealed proximally via a stent graft with persistent distal communication. To compare false lumen diastolic pressure between models, a false lumen pressure index (FPI%) was calculated for all simulations as FPI% = (false lumen diastolic pressure/true lumen diastolic pressure) x 100. RESULTS In model A, the systolic pressure was slightly lower in the false lumen compared with the true lumen while the diastolic pressure (DP) was slightly higher in the false lumen (DP 66.45 +/- 0.16 mm Hg vs 66.20 +/- 0.12 mm Hg, P < .001, FPI% = 100.4%). In the absence of a distal tear (model B), diastolic pressure was elevated within the false lumen compared with the true lumen (58.95 +/- 0.10 vs 54.66 +/- 0.17, P < .001, FPI% = 107.9%). The absence of a proximal tear in the presence of a distal tear (model C) diastolic pressure was also elevated within the false lumen versus the true lumen (58.72 +/- 0.24 vs 56.15 +/- 0.16, P < .001, FPI% 104.6%). The difference in diastolic pressure was greatest with a smaller tear (3.2 mm) in model B. In model B, DBP increased by 13.9% (P < .001, R(2) 0.69) per 10 beat per minute increase in heart rate (P < .001) independent of systolic pressure. CONCLUSIONS In this model of chronic type B aortic dissection, diastolic false lumen pressure was the highest in the setting of smaller proximal tear size and the lack of a distal tear. These determinants of inflow and outflow may impact false lumen expansion and rupture during the follow-up period.

Importance of Refractory Pain and Hypertension in Acute Type B Aortic Dissection Insights From the International Registry of Acute Aortic Dissection (IRAD)

Background— In patients with acute type B aortic dissection, presence of recurrent or refractory pain and/or refractory hypertension on medical therapy is sometimes used as an indication for invasive treatment. The International Registry of Acute Aortic Dissection (IRAD) was used to investigate the impact of refractory pain and/or refractory hypertension on the outcomes of acute type B aortic dissection. Methods and Results— Three hundred sixty-five patients affected by uncomplicated acute type B aortic dissection, enrolled in IRAD from 1996 to 2004, were categorized according to risk profile into 2 groups. Patients with recurrent and/or refractory pain or refractory hypertension (group I; n=69) and patients without clinical complications at presentation (group II; n=296) were compared. “High-risk” patients with classic complications were excluded from this analysis. The overall in-hospital mortality was 6.5% and was increased in group I compared with group II (17.4% versus 4.0%; P =0.0003). The in-hospital mortality after medical management was significantly increased in group I compared with group II (35.6% versus 1.5%; P =0.0003). Mortality rates after surgical (20% versus 28%; P =0.74) or endovascular management (3.7% versus 9.1%; P =0.50) did not differ significantly between group I and group II, respectively. A multivariable logistic regression model confirmed that recurrent and/or refractory pain or refractory hypertension was a predictor of in-hospital mortality (odds ratio, 3.31; 95% confidence interval, 1.04 to 10.45; P =0.041). Conclusions— Recurrent pain and refractory hypertension appeared as clinical signs associated with increased in-hospital mortality, particularly when managed medically. These observations suggest that aortic intervention, such as via an endovascular approach, may be indicated in this intermediate-risk group. # Clinical Perspective {#article-title-24}Background— In patients with acute type B aortic dissection, presence of recurrent or refractory pain and/or refractory hypertension on medical therapy is sometimes used as an indication for invasive treatment. The International Registry of Acute Aortic Dissection (IRAD) was used to investigate the impact of refractory pain and/or refractory hypertension on the outcomes of acute type B aortic dissection. Methods and Results— Three hundred sixty-five patients affected by uncomplicated acute type B aortic dissection, enrolled in IRAD from 1996 to 2004, were categorized according to risk profile into 2 groups. Patients with recurrent and/or refractory pain or refractory hypertension (group I; n=69) and patients without clinical complications at presentation (group II; n=296) were compared. “High-risk” patients with classic complications were excluded from this analysis. The overall in-hospital mortality was 6.5% and was increased in group I compared with group II (17.4% versus 4.0%; P=0.0003). The in-hospital mortality after medical management was significantly increased in group I compared with group II (35.6% versus 1.5%; P=0.0003). Mortality rates after surgical (20% versus 28%; P=0.74) or endovascular management (3.7% versus 9.1%; P=0.50) did not differ significantly between group I and group II, respectively. A multivariable logistic regression model confirmed that recurrent and/or refractory pain or refractory hypertension was a predictor of in-hospital mortality (odds ratio, 3.31; 95% confidence interval, 1.04 to 10.45; P=0.041). Conclusions— Recurrent pain and refractory hypertension appeared as clinical signs associated with increased in-hospital mortality, particularly when managed medically. These observations suggest that aortic intervention, such as via an endovascular approach, may be indicated in this intermediate-risk group.

Type-selective benefits of medications in treatment of acute aortic dissection (from the International Registry of Acute Aortic Dissection [IRAD]).

The effects of medications on the outcome of aortic dissection remain poorly understood. We sought to address this by analyzing the International Registry of Acute Aortic Dissection (IRAD) global registry database. A total of 1,301 patients with acute aortic dissection (722 with type A and 579 with type B) with information on their medications at discharge and followed for ≤5 years were analyzed for the effects of the medications on mortality. The initial univariate analysis showed that use of β blockers was associated with improved survival in all patients (p = 0.03), in patients with type A overall (p = 0.02), and in patients with type A who received surgery (p = 0.006). The analysis also showed that use of calcium channel blockers was associated with improved survival in patients with type B overall (p = 0.02) and in patients with type B receiving medical management (p = 0.03). Multivariate models also showed that the use of β blockers was associated with improved survival in those with type A undergoing surgery (odds ratio 0.47, 95% confidence interval 0.25 to 0.90, p = 0.02) and the use of calcium channel blockers was associated with improved survival in patients with type B medically treated patients (odds ratio 0.55, 95% confidence interval 0.35 to 0.88, p = 0.01). In conclusion, the present study showed that use of β blockers was associated with improved outcome in all patients and in type A patients (overall as well as in those managed surgically). In contrast, use of calcium channel blockers was associated with improved survival selectively in those with type B (overall and in those treated medically). The use of angiotensin-converting enzyme inhibitors did not show association with mortality.