Trends and Outcomes in Heart Transplantation over the Past Three Decades: A Single Tertiary Center Experience in Israel

BACKGROUND

Heart transplantation (HT) is the treatment of choice for patients with end-stage heart failure. The HT unit at the Sheba Medical Center is the largest of its kind in Israel.

OBJECTIVES

To evaluate the experience of HT at a single center, assess trends over 3 decades, and correlate with worldwide data.

METHODS

Between 1990 and 2017, we reviewed all 285  adult HT patients. Patients were grouped by year of HT: 1990-1999 (decade 1), 2000-2009 (decade 2), and 2010-2017 (decade 3).

RESULTS

The percentage of women undergoing HT has increased and etiology has shifted from ischemic to non-ischemic cardiomyopathy (10% vs. 25%, P = 0.033; 70% vs. 40% ischemic, for decades 1 vs. 3, respectively). Implantation of left ventricular assist device as a bridge to HT has increased. Metabolic profile has improved over the years with lower low-density lipoprotein, diabetes, and hypertension after HT (101 mg/dl, 27%, and 41% at decade 3, respectively). There has been a prominent change in immunosuppressive treatments, currently more than 90% are treated with tacrolimus, compared with 2.7% and 30.9% in decades 1 and 2, respectively (P < 0.001). Cardiac allograft vasculopathy (CAV) rates have declined significantly (47% vs. 17.5% for decades 1 and 2, P < 0.001) as have the combined endpoint of CAV/death. Similarly, the current incidence of acute rejections is significantly lower.

CONCLUSIONS

Our analysis of over 25 years of a single-center experience with HT shows encouraging improved results, which are in line with worldwide standards and experience.

Risk of early, intermediate, and late rejection following heart transplantation: Trends over the past 25 years and relation to changes in medical management. Tertiary center experience: The Sheba Heart Transplantation Registry

AIM

To explore the trends in the risk for rejection following heart transplantation (HT) over the past 25 years, and their relation to changes in medical management.

METHODS

The study population comprised 216 HT patients. Rejection periods were defined as follows: 0-3 months (early), 3-12 months (intermediate), and 12+ months (late). HT era was dichotomized as follows: 1991-1999 (remote era) and 2000-2016 (recent era). Medication combination was categorized as newer (TAC, MMF, and everolimus) vs older therapies (AZA, CSA).

RESULTS

Multivariate analysis showed that patients who underwent HT during the recent era experienced a significant reduction in the risk for major rejection. These findings were consistent for early (OR = 0.44 [95% CI 0.22-0.88]), intermediate (OR = 0.02 [95% CI 0.003-0.11]), and late rejections (OR = 0.18 [95% CI 0.05-0.52]). Using the year of HT as a continuous measure showed that each 1-year increment was independently associated with a significant reduction in the risk for early, intermediate, and late rejections (5%, 21%, 18%, respectively). In contrast, the risk reduction associated with newer types of immunosuppressive therapies was not statistically significant after adjustment for the treatment period.

CONCLUSIONS

Major rejection rates following HT have significantly declined over the past 2 decades even after adjustment for changes in immunosuppressive therapies, suggesting that other factors may also play a role in the improved outcomes of HT recipients.

Metformin therapy reduces the risk of malignancy after heart transplantation

BACKGROUND

Malignancy and diabetes mellitus (DM) cause significant morbidity and mortality after heart transplantation (HTx). Metformin, one of the most commonly used anti-diabetic drugs worldwide, has also been shown to exhibit anti-tumor activity. We therefore investigated the association between metformin therapy and malignancy after HTx.

METHODS

The study population comprised 237 patients who underwent HTx between 1991 and 2016 and were prospectively followed-up. Clinical data were recorded on prospectively designed forms. The primary outcome was any cancer recorded during 15 years of follow-up. Treatment with metformin and the development of DM after HTx were assessed as time-dependent factors in the analyses.

RESULTS

Of the 237 study patients, 85 (36%) had diabetes. Of the DM patients, 48 (56%) were treated with metformin. Kaplan-Meier survival analysis showed that, at 15 years after HTx, malignancy rate was 4% for DM patients treated with metformin, 62% for those who did not receive metformin and 27% for non-DM patients (log-rank test, p < 0.0001). Consistently, multivariate analysis showed that for DM patients, metformin therapy was independently associated with a significant 90% reduction (hazard ratio = 0.10; 95% confidence interval 0.02 to 0.40; p = 0.001) in the risk of the development of a malignancy. DM patients who were treated with metformin had a markedly lower risk (65%; p = 0.001) for the development of a malignancy or death after HTx as compared with non-DM patients.

CONCLUSIONS

Our findings suggest that metformin therapy is independently associated with a significant reduction in the risk of malignancy after HTx.

The impact of gender mismatching on early and late outcomes following heart transplantation

Aims

The role of donor/recipient gender matching on the long‐term rejection process and clinical outcomes following heart transplantation (HT) outcomes is still controversial. We aim to investigate the impact of gender matching on early and long‐term outcome HT.

Methods and results

The study population comprised 166 patients who underwent HT between 1991 and 2013 and were prospectively followed up in a tertiary referral centre. Early and late outcomes were assessed by the type of donor–recipient gender match (primary analysis: female donor–male recipient [FD–MR, n = 36] vs. male donor–male recipient [MD–MR, n = 109]). Early mortality, need for inotropic support, length of hospital stay, and major perioperative adverse events did not differ between the FD–MR and MD–MR groups. However, the FD–MR group experienced significantly higher rates of early major rejections per patient as compared with the MD–MR group (1.2 ± 1.6 vs. 0.4 ± 0.8; P = 0.001), higher rates of overall major rejections (16 vs. 5.5 per 100 person years; P < 0.05), and higher rate of cardiac allograft vasculopathy (43% vs. 20%; P = 0.01). Kaplan–Meier survival analysis showed that the cumulative probabilities of survival free of rejections and major adverse events were significantly higher in MD–MR group (P = 0.002 and 0.001, respectively). Multivariate analysis showed that FD–MR status was associated with >2.5‐fold (P = 0.03) increase in the risk for rejections and with a >3‐fold (P = 0.01) increase in the risk for major adverse events during follow‐up.

Conclusions

Donor–recipient gender mismatch is a powerful independent predictor of early and late rejections and long‐term major adverse events following HT.

In-stent restenosis and remote coronary lesion progression are coupled in cardiac transplant vasculopathy but not in native coronary artery disease

OBJECTIVES

The purpose of this study was to describe the clinical, angiographic, and histological features of concomitant in-stent restenosis (ISR) and cardiac allograft vasculopathy (CAV) progression.

BACKGROUND

Cardiac allograft vasculopathy is a major challenge to long-term success of heart transplantation. Coronary stenting for CAV is hampered by ISR.

METHODS

Quantitative coronary angiography compared late lumen loss (LL) at stented and reference, non-stented segments during 1-year follow-up in post-heart transplant and control atherosclerosis patients. Stented and non-stented arteries with CAV were also obtained post-mortem for immunohistochemical analysis.

RESULTS

In 37 stented lesions (25 patients), 1-year binary restenosis occurred in 37.8%. Patients with ISR had higher long-term cardiac death/myocardial infarction rates than patients without ISR (53.8% vs. 9.1%, p = 0.03). In the same 25 patients, 34 CAV lesions with non-significant obstructions were identified as reference controls. After 1 year, patients who developed ISR also had more control lesion LL (0.78 +/- 0.38 mm vs. 0.39 +/- 0.27 mm, p < 0.006) compared to patients without ISR. In the post-transplant patients, in-stent LL was closely coupled to control segment LL (R(2) = 0.63, p < 0.05). Conversely, in native atherosclerosis patients, ISR and remote disease progression were not correlated. Histological staining of stented and control arteries from CAV patients revealed similar pathologies common to ISR and non-intervened CAV segments.

CONCLUSIONS

Progression of CAV at non-intervened segments and ISR correlate strongly and share common histopathology. Optimized treatment for patients with aggressive CAV needs to address the widespread nature of this disease, even when it presents as an initially focal lesion.

Left main coronary artery atresia: extremely rare coronary anomaly in an asymptomatic adult and an adolescent soccer player

Left main coronary artery atresia is a very rare coronary anomaly with only 33 cases reported in the literature, of whom only 1 patient is asymptomatic. Pediatric patients are usually very symptomatic early in life (dyspnea, syncope, failure to thrive, ventricular tachycardia, and sudden death), whereas adult patients begin showing symptoms (angina or sudden death) only at an advanced age. Given the high risk related to the presence of left main coronary artery atresia, and in view of the good results obtained by coronary artery bypass surgery, coronary artery revascularization should always be considered as the possible treatment of choice for establishing adequate myocardial blood flow.

Subclavian coronary steal syndrome: an obligatory common fate between subclavian artery, internal mammary graft and coronary circulation

The long-term patency of the left internal mammary artery (IMA) has made it the preferred conduit for myocardial revascularization. The proximal segment of the subclavian artery becomes functionally connected to the coronary circulation as a result of IMA implantation during coronary artery bypass surgery. The subclavian coronary steal syndrome results from stenosis in the left subclavian artery proximal to the IMA, compromising blood flow to the myocardium. We describe 7 patients, aged 55-75 years, 1.7-10.5 years after coronary bypass who presented with recurrent angina due to subclavian artery stenosis. The IMA graft was found open in each patient. A true steal mechanism was not demonstrated, casting doubt on the syndrome's traditional name. Angioplasty and stenting of the subclavian artery resulted in the immediate disappearance of angina and continuous benefit at a follow-up of 3-32 months. The subclavian coronary steal syndrome, although rare, is a severe condition readily treated by angioplasty and stenting.

Blunted responses of doppler-derived aortic flow parameters during whole-body heavy isometric exercise in heart transplant recipients

BACKGROUND

Relatively light isometric exercise (handgrip) in heart transplant recipients induces attenuated increments in heart rate, blood pressure, and systemic vascular resistance, but hemodynamic response to whole-body, heavy isometric exercise is unknown. The aim of our study was to investigate the influences of whole-body, heavy, isometric exercise on Doppler-derived parameters in these patients.

METHODS

We investigated 18 patients, aged 54.0 +/- 2 years, 1.6 +/- 1.0 years after cardiac transplantation and 18 sedentary healthy volunteers, aged 51.8 +/- 4 years (p = not significant). Patients performed supine, isometric exercise by stretching a whole-body isometric device at 50% of maximal voluntary contraction for 3 minutes.

RESULTS

Resting heart rate, blood pressure, and rate-pressure product were higher in transplanted patients when compared with the healthy volunteers (p < 0.001 for all). However, during isometric exercise, these parameters increased to a lesser extent in the transplanted compared with the healthy subjects-heart rate, 12% vs 40% (p < 0.001); mean arterial pressure, 20% vs 27% (p < 0.05); and rate-pressure product, 39% vs 85% (p < 0.001). In the healthy volunteers, peak-flow velocity, mean acceleration, flow-velocity integral, and stroke volume decreased by 30% to 40% with isometric exercise (p < 0.001 for all), whereas systemic vascular resistance increased by 36% (p < 0.001) and cardiac output did not change. In the transplanted patients, all above parameters remained unchanged. Heavy, whole-body isometric exercise was well tolerated in heart transplant recipients in this study, without hemodynamic deterioration or other complications.

CONCLUSIONS

With whole-body, heavy isometric exercise, Doppler-derived aortic flow parameters demonstrate blunted responses or remain unchanged among heart transplant recipients. The observed phenomenon may have implications for studies of exercise physiology in transplant recipients.

Attenuated responses of Doppler-derived hemodynamic parameters during supine bicycle exercise in heart transplant recipients

The aim of this study was to characterize Doppler-derived hemodynamic parameters in heart transplant recipients at rest and during symptom-limited supine bicycle exercise. Eighteen sedentary patients aged 54.0 +/- 2 years, 1.6 +/- 1.0 years following cardiac transplantation, and 18 sedentary healthy volunteers aged 51.8 +/- 4 years were investigated. Basic hemodynamic parameters and Doppler-derived parameters were recorded at rest and at peak dynamic exercise. Resting heart rate, blood pressure and rate-pressure product were higher in the transplanted patients (p < 0.001). However, in comparison with the resting state, the increase in these parameters at exercise was lower in heart transplant recipients. In the healthy, dynamic exercise induced an increase in peak flow velocity, mean acceleration, flow velocity integral, stroke volume, cardiac output and cardiac index (p < 0.001 for all) while systemic vascular resistance, ejection time and acceleration time decreased (p < 0.001 for all). The following parameters increased in the transplanted patients at dynamic exercise: peak flow velocity, cardiac output and cardiac index (p < 0.001), mean acceleration (p < 0.01) and flow velocity integral (p < 0.05). Ejection time decreased (p < 0.05) and acceleration time and systemic vascular resistance remained unchanged. In conclusion, at rest peak flow velocity, mean acceleration, flow velocity integral and stroke volume are lower in the transplanted than in the healthy controls, while cardiac output, cardiac index and systemic vascular resistance are equal. Our study demonstrates attenuated responses of basic hemodynamic parameters and Doppler-derived cardiovascular indices at symptom-limited supine bicycle exercise in heart transplant recipients compared to healthy volunteers.

The significance of persistent ST elevation versus early resolution of ST segment elevation after primary PTCA

OBJECTIVES

To determine the prevalence and clinical significance of early ST segment elevation resolution after primary percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction (AMI).

BACKGROUND

Despite angiographically successful restoration of coronary flow early during AMI, adequate myocardial reperfusion might not occur in a substantial portion of the jeopardized myocardium due to microvascular damage. This phenomenon comprises the potentially beneficial effect of early recanalization of the infarct related artery (IRA).

METHODS

Included in the study were 117 consecutive patients who underwent angiographically successful [Thrombolysis in Myocardial Infarction (TIMI III)] primary PTCA. The patients were classified based on the presence or absence of reduction > or =50% in ST segment elevation in an ECG performed immediately upon return to the intensive cardiac care unit after the PTCA in comparison with ECG before the intervention.

RESULTS

Eighty-nine patients (76%) had early ST segment elevation resolution (Group A) and 28 patients (24%) did not (Group B). Group A and B had similar clinical and hemodynamic features before referring to primary PTCA, as well as similar angiographic results. Despite this, ST segment elevation resolution was associated with better predischarge left ventricular ejection fraction (LVEF) (44.7 +/- 8.0 vs. 38.2 +/- 8.5, p < 0.01). Group B patients, as compared with those of Group A, had a higher incidence of in-hospital mortality (11% vs. 2%, p = 0.088), congestive heart failure (CHF) [28% vs. 19%, odds ratio (OR) = 4, 95% confidence interval (CI) 1 to 15, p = 0.04], higher long-term mortality (OR = 7.3, 95% CI 1.9 to 28, p = 0.004 with Cox proportional hazard regression analysis) and long-term CHF rate (OR = 6.5, 95% CI 1.3 to 33, p = 0.016 with logistic regression).

CONCLUSIONS

Absence of early ST segment elevation resolution after angiographically successful primary PTCA identifies patients who are less likely to benefit from the early restoration of flow in the IRA, probably because of microvascular damage and subsequently less myocardial salvage.

Double-helical CT as a new tool for tracking of allograft atherosclerosis in heart transplant recipients

RATIONALE AND OBJECTIVES

Tracking the progression of allograft atherosclerosis in heart transplant recipients is currently accomplished using invasive techniques. If its monitoring feasibility is demonstrated, spiral CT could be a non-invasive alternative for this objective.

METHODS

Twenty-four consecutive heart transplant patients (21 men, 3 women, mean age 55 +/- 11 years) were scanned using double-helical CT. The first scan was performed 1.9 +/- 1.3 years after transplantation. After 2 years of follow-up, 4 patients died and the remaining 20 underwent a second scan. All scans were performed according to a previously reported double-helical CT protocol.

RESULTS

The incidence of coronary calcification at the first scan was 4.2% (1/24); it increased to 40% (8/20) at the second scan (P < 0.001). Spiral CT identified new but very mild calcific deposits in seven patients with a mean total calcium score of 6.7 +/- 4.0.

CONCLUSIONS

Double-helical CT is a viable tool to diagnose and track newly developed allograft atherosclerosis.

Prostaglandin E1 during angioplasty as preventative therapy for coronary restenosis

The effect of intravenous prostaglandin E ( 1 ) (PGE ( 1 ) ) on the incidence of restenosis after elective percutaneous transluminal coronary angioplasty (PTCA) was studied in a prospective, single-blind, randomized trial of 30 patients. Group I (12 patients) received only the conventional medications before and after protocol, and group II (18 patients) received intravenous PGE ( 1 ) infusion for 24 hours starting at least 2 hours before angiography after hemodynamically based titration to a mean dosage of 16 +/- 3 ng/kg/min (range, 10-20 ng/kg/min). All patients received aspirin orally, beginning 24 hours before PTCA and continuing for 6 months, and intravenous heparin at 1000 U/h for 24 hours commencing with the beginning of catheterization before PTCA. Recatheterization was performed routinely at 6 months after PTCA, or earlier when clinically indicated. Angiographic evaluations were made by both visual and quantitative assessment. No significant side effects of PGE ( 1 ) treatment were observed. Only 17% of patients treated by PGE ( 1 ) experienced angina pectoris during 6-month follow-up period, as compared with 42% of patients who received conventional treatment (p = 0.13). Re-PTCA was more frequent in patients receiving conventional therapy than in those receiving PGE ( 1 ) (42% versus 11%; p = 0.06). The use of PGE ( 1 ) during PTCA was associated with 17% restenosis (both by computer and by visual evaluation) 6 months post-PTCA as compared with 33% and 50% restenosis (by computer and by visual evaluations, respectively) in the conventional group (p < 0.05). In conclusion, PGE ( 1 ) appears to decrease coronary restenosis 6 months after PTCA.

Coronary calcium as a reliable tool for differentiating ischemic from nonischemic cardiomyopathy

In conclusion, the presence or absence of coronary calcium as detected by this rapid technique represents a simple and reliable noninvasive sign for the differential diagnosis between ischemic and nonischemic DC.

Rapid resolution of ST elevation and prediction of clinical outcome in patients undergoing thrombolysis with alteplase (recombinant tissue-type plasminogen activator): results of the Israeli Study of Early Intervention in Myocardial Infarction

Alteplase (recombinant tissue-type plasminogen activator (rt-PA)) was infused within four hours of onset of symptoms in 286 patients with acute myocardial infarction. Delayed coronary angiography was performed 72 hours after admission with coronary angioplasty if indicated. Electrocardiographic monitoring was continuous during the first hour of treatment. The sum of the ST segment elevations (sigma ST) was calculated on electrocardiograms recorded at entry and an hour later. ST elevations resolved rapidly within one hour of treatment in 189 patients and persisted in 97 patients. Rapid resolution of ST elevation correlated with angiographic coronary patency as determined by coronary angiography 72 hours after admission. The patients with rapid resolution of sigma ST had significantly smaller infarcts and a better clinical outcome than the patients with persistent ST elevation. sigma ST values at entry and one hour after treatment had no additional independent predictive value. Rapid resolution of ST elevations in patients undergoing thrombolysis with alteplase was associated with a significantly smaller release of creatine kinase, better preservation of left ventricular function, lower morbidity, and less short and long term mortality. Rapid resolution of sigma ST elevation is an efficient indicator of clinical outcome in groups of patients with acute myocardial infarction undergoing thrombolysis with alteplase.

Importance of reciprocal ST segment depression in leads V5 and V6 as an indicator of disease of the left anterior descending coronary artery in acute inferior wall myocardial infarction

The purpose of this study was to determine the coronary angiographic correlations (specifically disease of the left anterior descending coronary artery) of reciprocal ST segment depression appearing during inferior acute myocardial infarction. Forty six patients (41 men and five women; mean age 56 years) were allocated into two groups based on the extent of precordial ST segment depression: widespread (V1-V6) ST depression v localised (V1-V4) ST depression. Patients with no reciprocal ST depression or patients with ST depression in V1-V4 but with ST elevation in V5 and V6 (inferolateral acute myocardial infarction) were excluded. All patients were catheterised during hospital admission for infarction. Twenty four of the 28 patients with ST depression in V1-V6 had significant lesions in the left anterior descending coronary artery whereas 16 of the 18 patients with ST depression in V1-V4 had insignificant or no lesions in the left anterior descending artery. The sensitivity, specificity, and positive and negative predictive values of widespread ST depression in predicting disease in the left anterior descending coronary artery were 92%, 80%, and 86% and 89% respectively. In patients with inferior acute myocardial infarction and precordial ST depression, the extent of ST depression is of clinical significance. Widespread (V1-V6) ST depression suggests disease of the left anterior descending coronary artery, whereas localised ST depression (V1-V4) indicates its absence.

Should thrombolytic therapy be administered in the mobile intensive care unit in patients with evolving myocardial infarction? A pilot study

The growing recognition of the importance of early thrombolysis in evolving myocardial infarction was the basis for the present study, which evaluated the effectiveness, feasibility and safety of prehospital thrombolytic therapy. In a relatively small study, 118 patients were allocated to receive either prehospital treatment with recombinant tissue-type plasminogen activator (rt-PA) in the mobile intensive care unit (group A, 74 patients) or hospital treatment (group B, 44 patients). A total of 120 mg of rt-PA was infused over a period of 6 h. All patients were fully heparinized and underwent radionuclide left ventriculography and coronary angiography during hospitalization. Although group A was treated significantly earlier than group B after onset of symptoms (94 +/- 36 versus 137 +/- 45 min, respectively; p less than 0.001), no significant differences were observed between the groups in 1) extent of myocardial necrosis, 2) global left ventricular ejection fraction at discharge, 3) patency of infarct-related artery, 4) length of hospital stay, and 5) mortality at 60 days. However, a trend to a lower incidence of congestive heart failure at hospital discharge was observed in the prehospital-treated compared with the hospital-treated group (7% versus 16%, respectively; p = NS). No major complications occurred during transportation. It is concluded that myocardial infarction can be accurately diagnosed and thrombolytic therapy initiated relatively safely during the prehospital phase by the mobile intensive care team, thus instituting a beneficial clinical trend in favor of prehospital thrombolysis.

Characterization of regional left ventricular contraction by curvature difference analysis

A method which characterizes the contraction of the left ventricle (LV) by changes in the LV endocardial contour curvatures is presented. A normalized curvature difference function (NCDF) is defined by the difference between the (normalized) curvature functions of end diastolic (ED) and end systolic (ES) contours. Unlike wall-motion based procedures, NCDF is independent of any reference system and of the method used for ED-ES shape alignment. Normal and pathological diagnosis criteria were first established based on right anterior oblique (RAO) projection ventriculograms of a study group which included 58 normal and 28 abnormal patients. Patients with an infarcted myocardial region differed from the characteristic NCDF pattern of normals and exhibited regionally defined irregularities. The diagnosis criteria were then applied to a total of 159 patients in two groups in two independent laboratories. One group (in Israel) included 49 cases (20 normals, 29 abnormals); the second (in France) included 108 cases (48 normals, 60 abnormals). These two groups yielded similar sensitivity (97% and 97%) and specificity (90% and 100%) in detection of abnormality of the ventricle. When tested against other quantitative wall motion techniques, the NCDF shwos a regional sensitivity of 95%, indicating that curvature difference analysis is a potential tool for the automatic and objective diagnosis of regional LV function abnormalities.

Two-dimensional echocardiographic analysis of proximal left main coronary artery in humans

The left main coronary artery (LMCA) was evaluated in 100 consecutive patients (88 men and 12 women; mean age 63 years) with anginal syndrome, all in New York Heart Association classes II and III. Each patient underwent two-dimensional echocardiography (2DE) from the parasternal short-axis and apical four-chamber views. Coronary angiography was subsequently performed within 24 hours. The LMCA was directly measured by 2DE and coronary angiography at its widest point. Each echocardiogram was blindly evaluated for LMCA aneurysm or obstruction. Eight patients (8%) were excluded because of inadequate visualization of the LMCA. The mean 2DE measurement was 4.4 +/- 0.9 mm vs 4.2 +/- 0.8 mm on coronary angiography (r = 0.86). Atherosclerotic aneurysms of the LMCA were correctly diagnosed in two patients by 2DE. LMCA stenosis (greater than 50%) was found in 11 patients on coronary angiography; three of them had ostial or proximal lesions, three had middle lesions, and five had distal lesions. 2DE correctly diagnosed all three ostial lesions, two of three middle lesions, but only two of five distal lesions. In four patients, dense echoes in the LMCA caused a false positive diagnosis. It was concluded that: the LMCA can be visualized and correctly measured by 2DE; atherosclerotic aneurysms can be detected; and 2DE is yet unable to screen patients for LMCA lesions; however, 2DE is a promising method for evaluating proximal and especially ostial LMCA stenosis.

Changes in systemic vascular resistance detected by the arterial resistometer: preliminary report of a new method tested during percutaneous transluminal coronary angioplasty

A recently developed apparatus provides on-line continuous monitoring of systemic vascular resistance (SVR) by means of simple computer analysis of the peripheral arterial waveform. The fundamental equation of this method is Ri = P'/(dP/dt), where dP/dt is the peak dP/dt of the peripheral arterial waveform, P' is the pressure at time of peak dP/dt, and Ri is a resistance index that bears a direct relation to SVR. Eleven patients undergoing percutaneous transluminal coronary angioplasty (PTCA) were studied to evaluate the changes in SVR associated with myocardial ischemia (angina detection). There were 49 balloon inflations, all of which were associated with an increase in Ri (from 38.4 +/- 12 to 81.2 +/- 36 X 10(-3) sec; p less than .01) and a decrease in dP/dt (from 2076 +/- 257 to 1327 +/- 326 mm Hg/sec; p less than .01). In 42 of the balloon inflations these changes were associated with electrocardiographic ST-T changes and in 23 it was also associated with anginal pain. When angina was present, a further increase in Ri (to 97.5 +/- 43 X 10(-3) sec; p less than .01) and a decrease in dP/dt (to 1218 +/- 338 mm Hg/sec; p less than .01) was observed. It was found that myocardial ischemia is associated with an increase in the resistance index and a decrease in dP/dt and can be detected by the resistometer.

Correlation between effects of hydralazine on force and on the adenyl cyclase system of ventricular myocardium in dogs and cats

Hydralazine is a potent arteriolar dilator, which increases cardiac output in patients with heart failure. Previous studies suggested that these beneficial effects might be due in part to a positive inotropic effect. The present study further investigated the effect of hydralazine on myocardial contractility and adenyl cyclase activity. In isolated cat papillary muscles, bath concentrations of hydralazine up to 10(-4) mol X litre-1 did not alter force development, whereas 10(-3) mol X litre-1 hydralazine increased isometric force by 31%. This effect was blocked by 10(-6) mol X litre-1 propranolol and was absent after catecholamine depletion produced by previous reserpine treatment. In canine ventricular myocardium hydralazine in all concentrations used (10(-7) to 10(-3) mol X litre-1) increased control adenyl cyclase activity. This increase was statistically significant in 10(-6) to 10(-3) mol X litre-1 concentrations, reaching a maximum of 69.5% at 10(-4) mol X litre-1. In cat ventricular myocardium 10(-6) to 10(-3) mol X litre-1 hydralazine increased the cyclic AMP production, although to a lesser magnitude than that in canine tissue. Hydralazine 10(-5) mol X litre-1 produced a 37.8% increase, and the maximum effect of 45.2% occurred at 10(-3) mol X litre-1. The positive effects of hydralazine were completely abolished by the addition of propranolol in dogs as well as in cats. Thus the adenyl cyclase stimulation induced by hydralazine is mediated through the beta receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Fate of nonobstructive aneurysmatic coronary artery disease: angiographic and clinical follow-up report

The incidence of coronary aneurysmatic dilatation without coronary stenosis is rare, and the clinical course of such an entity is unknown. We present five adult patients, four men and one woman, with such an anatomic finding. The age range was 44 to 60 years. In four patients the aneurysmatic dilatations involved multiple coronary sites. The clinical course in all five patients was suggestive of coronary insufficiency. Despite no obstructive disease, two of the patients developed transient ischemic ECG changes accompanied by chest pain, and another two patients demonstrated ischemic exercise nuclear ventriculography response. In time, all five patients developed acute myocardial infarction and recatheterization revealed complete occlusion of a previously nonstenosed aneurysmatic vessel. More information is needed in order to guide therapy. However, prevention of thrombus formation and close follow-up is highly recommended.